I think you're doing Tristan wrong. He doesn't think he's better than anyone else, he simply thinks (and very grudgingly I have to admit it's true) that he's better than you.
Now to get back on the "Who's a chav" topic:
In the car world, a chav is a person who modifies his car with useless at best or even dangerous additions. A quick glance on what would make you qualify as a chav:
1) Rims: You don't even have to have alloy wheels, just calling them "rims" makes you a chav. There are nice wheels admittedly, but as soon as you use broader tyres than the car has stock and/or rediculously large wheel diameters (say 2-3" larger than the stock wheels), you are a chav. Don't even make me mention chrome and spinners.
2) Spoilers: If your car features one, you're a chav. Even if it came with the stock car. Spoilers have no purpose in oridnary traffic.
3) Exhausts: As a rule of thumb: if you can fit a fist into your exhaust, you're a chav. Even more so if you just bolted a "phat" pipe on the end without upgrading the whole exhaust system.
4) Sideskirts: See "2) Spoilers".
5) Soundsystem: Every pound spend more than you'd need to listen to musik and the traffic announcements when going on the topmost legal speed is a pound that directly increases your personal chav meter. For every speaker that exceeds the car limit of four, your chav meter multiplies. A subwoofer multiplies it by 5.
6) Paint: Painting a car with the intention to draw looks rather than to prevent rust = you are a chav. Thinking that "vinyls" look cool makes you a chav.
7) Lowering the "ride": Every milimeter your car is lower than it was right out of the factory makes your chav count go up. Having a lowrider style jumpedy-jump suspension: chav alert.
8) Nitrous Oxide: Unless you are a professional drag racer, you are a chav if you have one of those. On a second thought: most dragracers would qualifiy as chavs anyways...
SO that should make everything clear. Ans sam, I'm sorry to say so, but you are one archetypical chav.
EDIT: Damn, answered prematurely, there were still 2 pages of this thread to read. Well, tough luck.