My favorite car of all time is Buckminster Fuller's 1933 Dymaxion Car. Shame it was a death trap.
From Open Culture:
The concept car didn't get much beyond the concept stage. Only three original versions were built, one of which rolled over at the 1933 World's Fair, leaving the driver dead, three passengers injured, and investors reluctant to bring the car to market. In 2010, the British architect Sir Norman Foster built a replica of the Dymaxion. You can see Dan Neil, of The Wall Street Journal, take the car on a harrowing test drive above. And if you're intrigued enough to learn more, you can hunt down the 2012 documentary called The Last Dymaxion (watch a trailer of the film here).