Dissenting Opinion by
Montgomery, J.:Consistently in the past we have held that án opinion as to the speed, of a moving vehicle may not be expressed unless the vehicle had been seen moving for a distance that would adequately present an opportunity to form such opinion. Guzman v. Bloom, 413 Pa. 576, 198 A. 2d 499 (1964). In the present case the appellee-plaintiff did not have that opportunity, nor did any*478one else. In order to establish that his car had been struck with great force, thereby implying speed which might be considered as negligent operation (although his car had been moved only 30 feet and showed no evidence of contact), he was permitted to offer his opinion as a physicist which was based on facts on which his inexpert opinion of speed could not be predicated.
This was prejudicial error and requires a new trial which I would grant.
I respectfully dissent.
Jacobs and Spaulding, JJ., join in this dissenting opinion.