20K? Shame about no used cars. You can pick up a 2000-2003 E39 M5's (that's 7-10 years old, 400 horsepower, rear-wheel-drive, BMW reliability and build quality, practical saloon, 80,000 or less miles) for $12,000-$15,000.
Plus tons of other cars (car-show quality C4 Corvettes for $14K or so, normal ones for $9K or prestine, classic, E24-era M6s that'll be worth a fortune in ten years or so, to name just two) can be found for less than $20K used. Shame. Huge, huge shame.... Just check out autos.yahoo.com if you want to have your mind changed.
As for new cars, hmm. I would say wait until we get some hot Fiesta of some kind, but that could be from three to never years.
How 'bout a one-two year old Honda Civic Si? My parents have kept some Honda's for 12 years and 250,000 miles, and we only got rid of it when it got a hole in the muffler and it cost more to fix it than the car was worth. :cheeky: Solid as rocks. Same goes for a two to three year old Honda S2000, which has a manual (shame about that rule, too. Glad you're enthusiastic about manuals later, though :) ) gearbox widely regarded to be the best ever.
Jeez, there's nothing interesting for under $20K new (don't say anything, Europeans - we're jealous already :cheeky: ).
Everything decent is $22,000 (2011 Mustang V6, which is as powerful as the 2010 GT.) Oh, new idea - take a look at your local Ford dealer, they'll be desperate to get 2010 Mustangs off the lot (at least once production of the 2011 ramps up), because no one will buy them next to the 2011s. So you could pick up a new 2010 V6 with a glass roof or something cool like that for a few grand under $20K.
-Leadfoot [is out of breath and done]