i have a isf with about 2500 miles on it and i want to make the car more fun. ive been looking at sikky headers, k&n typoon intake, borla exhaust, and some springs (tein?) and maybe a throttle controller. could you guys tell me what is the best performance part in every category. also none of those things would void the warranty right because of the new law? this is a bit off topic but what are some really nice light weight wheels?