LOL> uh. yeah cars are just WAY too heavy. You'd need some very large airfoils and quite a bit of power over what you would typically use in a GA aircraft. For example, i can move a Cessna 172 around on the ground with my bare hands. Good luck doing that with a sedan.
I understand that weight on ground for stability is completely different than air travel... but why not create a whole class of vehicles around this premise?
The only one I can remember is the SkyCar from Moller. He was a little ahead of the game with petrol based quad motors.