Opinion
THE COURT.In this action for damages for personal injuries, defendants General Motors Corporation and Fletcher Chevrolet, Inc., appeal from a judgment entered upon a jury verdict in favor of plaintiff.
About 9 p.m. on the evening of September 23, 1966, plaintiff Lillian Y. Horn was driving her 1965 Chevrolet station wagon down Laurel Canyon Boulevard, a curving Los Angeles street. She was accompanied by her two sons; her six-year-old son was in the front seat and her nine-year-old son in the rear. As she wound downhill, at approximately 25 miles per hour, a car rounding a curve suddenly swung into her lane, its headlights temporarily blinding her. She swerved to her right to avoid the car, bounced off the right curb across the street to the left and into a concrete reinforced abutment.
As she steered to the right, plaintiff brought her left hand across the horn cap in the center of the steering wheel; at the same time, with her right hand, she tried to hold her son on the front seat. She felt and saw something fly between herself and her son; it was later established that this was the horn cap. When the car hit the abutment, plaintiff felt a burning sensation as her face hit the “center part” of the steering wheel. The “center part,” following removal of the horn cap, contained three sharp prongs that held the horn cap in place. Plaintiff sustained a laceration of the chin, a displaced fracture of her jaw, a fracture of her left ear canal, and the loss of two teeth.
Plaintiff brought this action against defendant General Motors Corporation, the manufacturer of the station wagon, and defendant Fletcher Chevrolet, Inc., the dealer from whom she purchased it. The case was tried on the single theory of strict liability in tort based on a defective product. In detail plaintiff’s theory was that the automobile was defective in that the horn cap was easily removable in normal use of the vehicle thereby exposing three sharp prongs, and that, as a result, when plaintiff was involved in a collision not caused by defendants, she sustained injuries which were measurably aggravated because of this defect in design or manufacture. In short: the defective horn cap caused plaintiff injuries which were greater than the injuries she otherwise would have *366received as a result of the collision. The juiy returned a verdict against both defendants for damages in the sum of $45,000.
1. Cause of Action for Aggravation of Injuries Due to Defect
Defendants contend that they are not liable as a matter of law because a collision is not a normal, proper or intended use of an automobile and therefore the manufacturer is under no duty to design an automobile so as to prevent any aggravation of injuries resulting from a collision which occurs for reasons wholly unconnected with the design and manufacture of the automobile. (Evans v. General Motors Corporation (7th Cir. 1966) 359 F.2d 822; Hoenig & Werber, Automobile “Crashworthiness”: An Untenable Doctrine (1971) 20 Clev.St.L.Rev. 578.) In Cronin v. J.B.E. Olson Corp. (1972) 8 Cal.3d 121, 126 [104 Cal.Rptr. 433, 501 P.2d 1153], this court acknowledged the existence of this line of authority but specifically rejected it: “Although a collision may not be the ‘normal’ or intended use of a motor vehicle, vehicle manufacturers must take accidents into consideration as reasonably foreseeable occurrences involving their products. (Passwaters v. General Motors Corporation (8th Cir. 1972) 454 F.2d 1270, 1276; Larsen v. General Motors Corporation (8th Cir. 1968) 391 F.2d 495, 501-503; 80 Harv.L.Rev. 688, 689 (1967); contra, Evans v. General Motors Corporation (7th Cir. 1966) 359 F.2d 822, 825 . . . .) The design and manufacture of products should not be carried out in an industrial vacuum but with recognition of the realities of their everyday use.” In Cronin the driver of a bakery truck was injured when another vehicle forced the truck off the road and into a ditch. The impact broke an aluminum hasp holding the bread trays in place and the trays were driven forward against the driver, propelling him through the windshield. We upheld a verdict in favor of the plaintiff and against the manufacturer of the truck declaring that liability rested not on the basis that the hasp caused the collision “but only that its defectiveness was a substantial factor contributing to [the plaintiff’s] injuries.” (Id., at p. 127.)
In the instant case the jury was properly instructed to the effect that if the station wagon was defectively designed or manufactured in such a manner that the horn assembly caused plaintiff to sustain greater injuries in the collision than she would have otherwise sustained absent the defect, then the manufacturer and distributor of the vehicle would be liable to the extent of such aggravation of her injuries. This instruction contained a principle of liability consistent with our ruling in Cronin.
2. Sufficiency of the Evidence
Defendants claim that there is insufficient evidence to support the following three factual ingredients allegedly essential to plaintiff’s case: *367(a) That the design of the horn cap was defective; (b) that plaintiff’s jaw in fact came into contact with the center hub area of the steering wheel after displacement of the horn cap and exposure of the underlying prongs; and (c) that plaintiff’s injuries were aggravated due to contact with the exposed prongs in the center hub area of the steering wheel. We view the facts in the light most favorable to plaintiff, giving her the benefit of every reasonable inference and resolving all conflicts in her favor in accordance with the standard of review long adhered to by this court. (Crawford v. Southern Pacific Co. (1935) 3 Cal.2d 427, 429 [45 P.2d 183].)
(a) Plaintiff’s expert testified that the horn cap was defective in that it could be easily knocked off in the course of normal use of the car, thereby exposing the sharp prongs underneath and that there were several alternative ways of designing the horn cap to prevent its being knocked off. Defendants’ expert, on cross-examination after testifying that the purpose of the prongs was to keep the horn cap in place, acknowledged that it was foreseeable to the manufacturer that a driver’s hand would pass across the horn button while the steering wheel was being turned, that it was foreseeable that the vehicle would be subject to sudden stops and possible impacts, that the horn cap could have been affixed by screws thereby both eliminating the prongs and preventing the cap’s displacement, and that the increased cost, if any, of such an alternative would not have been significant. This evidence is clearly supportive of the jury’s implied finding that the fastening of the horn cap by three sharp prongs in such a way that it could be easily displaced and the prongs thereby exposed to possible contact by the driver during a collision or sudden stop, constituted a defect in design or manufacture. Defendants’ contention that this evidence is insufficient because it fails to establish that this design varies from the state-of-the-art as reflected in the design of other cars in the same year is without merit. We specifically rejected the necessity for such proof in establishing a defect in Cronin v. J.B.E. Olson Corp., supra, 8 Cal.3d 121, 125-126 (see Jiminez v. Sears, Roebuck & Co. (1971) 4 Cal.3d 379, 383 [93 Cal.Rptr. 769, 482 P.2d 681]).
(b) Although plaintiff" did not directly state that the horn cap came off" and that her face hit the exposed prongs, there was clearly substantial evidence which would support a finding by the juiy to that effect. Plaintiff" recalled her hand crossing over the center of the steering wheel; indeed during an experiment at trial the same hand movement resulted in the horn cap being knocked off". She felt and saw something *368fly between herself and her son after she brought her left hand across the steering wheel in swerving to the right in order to avoid the oncoming car. After the accident, she saw that the horn cap was detached. She distinctly recalled that her face had collided with the center part of the steering wheel and that she then experienced a burning sensation. There were no other sharp surfaces in the center of the steering wheel, and the injury pattern on plaintiff’s face matched the pattern of the exposed prongs.
(c) Defendants pointed out that plaintiff failed to present any evidence as to the type and severity of injuries she would have received if the horn cap had been in place, whereas defendants presented uncontradicted evidence to the effect that the force of the collision was such that plaintiff would have broken her jaw even if the horn cap had been in place. Therefore they argue that there is insufficient evidence to establish that the exposed prongs caused any injuries at all. To put the argument another way, since plaintiff’s jaw would have been broken by the collision in any event, the defect in the horn assembly actually caused no injury. Plaintiff’s expert testified that the force with which she struck the prongs was 100 times greater than the force with which she would have struck the surface of the horn cap when in place. The expert also testified that it was possible to construct a well secured horn cap of material which would collapse upon impact. In addition the jury had an opportunity to observe the hub area of the wheel with the horn cap off and the prongs exposed, and could reasonably infer from such observation that more damage would be done to a face striking the prongs instead of the horn cap itself.
We therefore conclude that the jury was warranted in finding, on substantial evidence, that the exposed prongs caused plaintiff to suffer greater injuries as a result of the collision than she would have received if the horn cap remained in place. In doing so the jurors were entirely free to reject defendants’ evidence to the contrary.1 {Foreman & Clark Corp. *369v. Fallon (1971) 3 Cal.3d 875, 890 [92 Cal.Rptr. 162, 479 P.2d 362]; Hicks v. Reis (1943) 21 Cal.2d 654, 659-660 [134 P.2d 788].) Having found that plaintiff suffered aggravated injuries, the jury was under a duty to fix the amount of damages from the evidence available. “It is the rule that one whose wrongful conduct has rendered the determination of damages uncertain cannot thereby escape liability . . . .” (Hutcherson v. Alexander (1968) 264 Cal.App.2d 126, 135 [70 Cal.Rptr. 366, 38 A.L.R.3d 636]; 4 Witkin, Summary of Cal. Law (8th ed.) § 846, p. 3140.) Defendants do not contend that the amount of damages was excessive.
3. Exclusion of Evidence Pertaining to Plaintiff’s Failure to Use
Seat Belts
Plaintiff’s station wagon was equipped with seat belts admittedly in good working order. She admitted that she was not using them at the time of the collision. At a hearing outside the jury’s presence, defendants offered to prove by the testimony of an expert that failure to use seat belts was a misuse of the automobile and that if plaintiff had been using the seat belts at the time of the accident, her injuries would have been substantially reduced. The trial court ruled such evidence inadmissible on the ground that plaintiff’s contributory negligence was not an issue. Defendants concede, as indeed they must, that ordinary contributory negligence is not a defense to an action for damages based on strict liability in tort (Luque v. McLean (1972) 8 Cal.3d 136, 145 [104 Cal.Rptr. 443, 501 P.2d 1163]); they urge, however, that since, as we pointed out in Luque, the form of contributory negligence known as assumption of risk is a defense to such an action the offered evidence was admissible on that ground. They argue that plaintiff consciously chose not to use her seat belt with the knowledge that such conduct would increase the risk of injury in the event of a collision, since she would probably be thrown about the interior of the car. In sum, defendants argue, plaintiff voluntarily and unreasonably proceeded to encounter a known danger.
In Luque we said: “ ‘The only form of plaintiff’s negligence that is a defense to strict liability is that which consists in voluntarily and unreasonably proceeding to encounter a known danger, more commonly referred to as assumption of risk. For such a defense to arise, the user or *370consumer must become aware of the defect and danger and still proceed unreasonably to make use of the product.’ (Italics added.) (Barth v. B. F Goodrich Tire Co. (1968) 265 Cal.App.2d 228, 243 . . . .)” (Luque v. McLean, supra, 8 Cal.3d at p. 145.) There is no evidence in the present record showing, or from which it can be reasonably inferred, that plaintiff was aware of the defect in this case, namely the easily removable horn cap exposing sharp prongs, or that she was aware of any danger caused by such defect. The evidence offered by defendants as to plaintiff’s failure to use her seat belt did not purport to show that plaintiff knew that the horn cap was defective and that her failure to use her seat belt would expose her to the risk of injury from the prongs beneath the horn cap in the event the cap itself came off. The offered evidence did not establish the defense of assumption of the risk, but at best indicated some negligence of a general nature on plaintiff’s part in not using the seat belt. We conclude that the trial court properly excluded the evidence in question.2
Defendants urge that this evidence was also admissible on the ground that it would tend to show that plaintiff’s failure to use a seat belt was the proximate cause of her injuries. However, this argument amounts to nothing more than a restatement of the inadmissible defense that plaintiff’s negligence in not using a seat belt contributed to or was a contributing cause of the accident. Defendants’ cognate claim that the proffered evidence was relevant to prove that some of plaintiff’s damages could have been avoided by reasonable action on her part is again merely another word formulation of the same inadmissible claim of contributory negligence.
Defendants’ final claim as to the admissibility of this evidence is to the effect that it would tend to prove that the product—the station wagon—was misused. It is true as indicated earlier in this opinion that if the product is put to a use by the consumer that is not reasonably foreseeable, then strict liability should not be imposed. (Cronin v. J.B.E. Olson Corp., supra, 8 Cal.3d 121, 126; Johnson v. Standard Brands Paint *371Co. (1969) 274 Cal.App.2d 331, 340 [79 Cal.Rptr. 194]; Prosser, Law of Torts (4th ed. 1971) pp. 668-669.) The simple answer to defendants’ argument is that the driving of an automobile without using a seat belt is an entirely foreseeable use of the vehicle.
4. Exclusion of Cumulative Evidence
The trial court is vested with discretion to limit the number of expert witnesses. (Evid. Code, § 723; Witkin, Cal. Evidence (2d ed. 1966) § 1096, p. 1014.) Defendants called four experts who gave their opinions as to the movements plaintiff’s body must have taken upon impact and uniformly concluded that she could not have struck the center area of the wheel. The trial court refused to allow defendants to introduce the same expert opinion evidence by a fifth expert, an employee of defendant General Motors. It is clear that this testimony was cumulative on the point.
The trial court has discretion to refuse to admit cumulative evidence. (Evid. Code, § 352; Estate of Wineteer (1917) 176 Cal. 28, 30-31 [167 P. 516].) Moreover, “the exclusion of evidence which has only a cumulative effect will not justify reversal on appeal, . . .” (Weller v. Chavarria (1965) 233 Cal.App.2d 234, 247; People ex rel. Dept, of Public Works v. Donovan (1962) 57 Cal.2d 346, 357 [19 Cal.Rptr. 473, 369 P.2d 1]; Pauly v. King (1955) 44 Cal.2d 649, 661 [284 P.2d 487].) Defendants have not shown that the fifth expert’s opinion would be anything other than cumulative. Their reliance on Evans v. Industrial Acc. Com. (1945) 71 Cal.App.2d 244 [162 P.2d 488], is of no avail since there the court merely determined that there was insufficient evidence on the point in issue to justify exclusion of the evidence as cumulative; in other words, in Evans the referee abused his discretion by not allowing any witnesses to corroborate the testimony of the party seeking workmen’s compensation. In the case at bench the evidence was truly cumulative and thus properly excluded.
Defendants introduced into evidence several motion pictures made by General Motors of the body movements of an unrestrained occupant of a car upon collision. When they sought to introduce on this point an additional motion picture made by an independent expert, the court excluded it as cumulative. However, the court did allow the expert who made the picture to testify as to the experiments which constituted its subject matter. Defendants have failed to show that the additional picture was not cumulative. Even if it were not cumulative, we do not see *372how defendants could have been prejudiced by the exclusion of the motion picture, since the court permitted the person who made the. picture to testify as to its content.
The judgment is affirmed.
Richardson, J., who was not a member of this court when the case was orally argued, did not participate.
Defendants’ failure to recognize that the jury was free to entirely disregard defendants’ evidence undercuts an additional argument raised in the briefs, to wit that defendants were relieved of liability because plaintiff sustained her injuries in an unusual, unexpected and bizarre manner. The supposed bizarren'ess of the accident depends solely upon the belief of defendants’ evidence that the unrestrained body of a driver in a similar collision would move forward upon impact and the driver’s chin would contact the upper rim of the wheel instead of the center part. Defendants’ argument, therefore, is that if plaintiff’s chin did contact the center part of the wheel, it defied normal physical laws and was thus so bizarre as to defeat liability. If. however, the jury disregarded defendants’ evidence of the normal trajectories of unrestrained bodies *369in collisions, as it was free to do, there is nothing bizarre about the injury at all—the car struck an abutment, throwing plaintiff forward so that her chin hit the center area of the wheel.
In the case at bench, judgment on the verdict in favor of plaintiff and against defendant was entered on December 15, 1971, well in advance of this court’s decision in Li v. Yellow Cab Co. (1975) 13 Cal.3d 804 [119 Cal.Rptr. 858, 532 P.2d 1226] (filed Mar. 31, 1975). In Li this court held that the rule of comparative negligence therein announced would be applicable only to cases “in which trial has not begun before the date this decision becomes final in this court [Apr. 30, 1975]. . . .” (13 Cal.3d at p. 829.) Under these circumstances we find no compelling reason to apply- the rule of comparative negligence to this case which was tried long before our decision in Li and in which on this appeal the issue of comparative negligence was neither briefed nor argued.