-IF you have an Front-Mount intercooler (ABD, FORGE etc..) your engine will run cooler hence, will perform better (if chipped).

-Cold Air Intakes and Exaust (like an IN and OUT for air) IF performance parts are put on the car, the air restriction will be a lot less coming in and even better coming out giving you more power to the turbocharger and the engine?.

-Stut bars and Sway bars, if you have both of them installed on a car, your car will handle better on corners and turns?

YES to all the your ???????...those are some of the first things people do,before going internal on the engine, or on the suspension.