You are quite correct... I finally remembered the car was a Frazer Nash and after a little digging on t'internet found a couple of better photo's.
Perhaps, though I'd like to think that earlier editions of mankind were a little more self confident than those that came later. Plus what flavor god would those chaps have had? They had to be thinking someone could see it though.
It would be exciting to think that ancient man had some contact or link to the stars. Though based on all the evidence we have discovered to date, there is no reason to think that is likely. Unless these visiting beings were the ultimate in preservation of the environment tourists - they left no traces and seemingly found nothing to take away. They also haven't been back AFAIK. The planet hopping idea is also a little beyond anything I can really imagine. We are able to do some pretty complicated things in 2024. The idea of manned expeditions to Mars is already 600 times further than the Moon. Neptune is about 12,000 times further than the moon. The next closest exo planet outside our solar system is 4.2 light years away...