Interesting stuff. A show on PBS a while back put some of these 'concept cars' on display. Most of them shared one characteristic: a complete lack of comfort and safety features. No radio, no heat, no AC, and please don't get in a wreck in one. Some of them have a small motor, and hold enough gas to get them onto the turntable at the show with the pretty girl.
Another prototype got my attention recently, it was an image being used as clickbait on the ad section of several sites I follow. A cute little round green car. I clicked once on the image, and nope, no information there, it was just spamming some penny stock.
So did a little research, and after a bit of searching, turned up the story of the pea car:
Turns out it was a prop used in this commercial:
So, there ya go. No safety features. The designers at Asylum Models put a small Honda engine in it, and the stunt driver sat with his knees up under his chin. Cute, though.