I havn't done much with my car, I replaced the tranny recently, and now I have to replace the rear left caliper, or rebuild it. Other than that, I cleared out the cats, which added QUITE a bit more power, as they were pretty clogged up. It sounds pretty good, too. That clarion touch screen player is GREAT. I would definitly recommend it. A good place is ebay, there is a store there with really good deals. It's called Finest Deals. I also love the 2.8 engine, not a dragster, but it really is a good engine. Plus, I'm one of 3 owners of older model Audis in my town, which is filled with plymoth lasers and mitsubishi eclipses. Pretty nice car. I couldn't really ask for much else (except for a new s4 *drool drool*)
