I had a 1:12 dollhouse when I was a kid, and a plastic Volkswagen for my ‘little people’ to drive around in.
Their alternative car was a plastic model my brother made, something green that looked like it was from the 1930s. Doors opened and everything :-)
Sort of like this - but green, and probably a different model with a ‘rumble seat’:
http://www.oldmodelkits.com/index.php?detail=13795
I still have a dollhouse fully furnished that I restored this winter maybe I can post a picture or 2 if you don’t mind.