I drove a FIAT in the early 70's for a few months. I think it was called the 600.

Very small, very slow and no A/C. It was not mine; I just had access to it through a friend who thought it was the greatest car in the world.

For total weirdness you can't beat the early Subaru 360's. Top speed of about 60, but they would get 50 mpg and had plenty of head room.

The Isetta is also an interesting choice. I never drove one, but they do have a rear engine and they, or at least some of them, were built by BMW.

Subaru 360 - Wikipedia, the free encyclopedia