Chris has posted a thorough comparison of a variety of car by their drag coefficients

I had no idea that a Ford Probe, a Vector, a Chevy Lumina APV (mini van), and a Jaguar XJ220 all had a .30 drag coefficient, remarkable!

But the 1948 Tucker was just .28! and the '35 Tatra was .21, better than the new Mercedes Benz CL E Class Coupe

go check it out