Try these websites
J3 Motorsport and
millteksports.com
I have a 2001 TT 225. Purchased it for about 23k...fully loaded 6speed manualy trans etc.. It only had 30k miles on it. I'm having J3racing do an ECM flash, exhaust, and intake mods performed in about 3 weeks. Approx cost around 3k ish. I may get a good torq and Hp bump of 35. Not too bad.