Rarest car... probably the '06 BMW M3 ZCP Competition Package car in Intergalagos Blue my wife drives on sunny days currently. No production #s out of BMW, but it is rare for sure. This is the American sister car to the uber rare European only CSL. We've added all the carbon fiber CSL goodies, but we don't have the super cool air intake assembly $$$$$ exclusive to the CSL cars. This car happens to be the funnest car to drive that I currently own. You can't beat the engineering of a German sports car IMHO.

Or the '05 Acura TL Aspec 6 Speed she drives on the other days. only 5% were 6 speeds, far fewer were Aspec package cars... probably something like 1-2% of all '05s. It has a "sport" VIN (1 yr only) which means it is a pre-"Type S" and we got stiffed the larger motor by buying a few months too early before the '06 Type S cars existed. Still got the big Brembos up front and tougher suspension.

Oh... you meant rare INTERESTING muscle cars? None. '70 Super Bee 383 4 speed bench seat post car is as rare as I've had in that department (still own). 1 of 1736 or something like that. Color is FE5 Red with a black C stripe. Not super rare/desirable, but uncommon and attractively equipped, and that's what I like in my women and my cars.