I dont know to much bout these things, but cars in general and what i would like to do with mine if only it wasnt my daily driver is as follows. only listed top 5. some other things might include boost controller, larger turbo, larger injectors, intercooler things like that, but i havent dont to much research on those things cause mine is N/A
1. suspension
2. intake
3. exhaust
4. brake system
5. weight reduction