UPDATE: I bought a 2007 Honda S2000 with 29,208 miles! Gray and Red and Black seats! 1 owner, perfect service records! Its amazing!
I would much rather have new car for 20k that isn't as fancy as a used car that would cost 20k. Used cars almost always have problems. If there weren't any problems, the original owner probably wouldn't have sold it. Sure, you'll find a few cars that just weren't right for someone, but the majority of used cars out there are being sold because the owner doesn't want to deal with them anymore. For 20k you can get a pretty damn nice new car that more than likely won't come with the headaches that used cars are prone to.