I wonder if this opinion would stand if it was law to wear a helmet while driving your car. I'm sure wearing a helmet while driving would save lives and prevent head injuries.
I wouldn't be so sure here. In general, helmets protect against impact collision which I understand to be reasonably rare in car crashes (looking at the average household car, not some sort of track car). Usually it is the car getting hit and the person inside being thrown around as a result. On the other hand, the helmet would increase the weight of the head which would probably result in more whiplash type injuries.