$500 - Catback
$1500 - JDL Headers + Tune
$5000 - Over/Front Pipe, Intake System, black Enkei RPF1s, Michellin Pilot SSs for road/track, new set of Primacy HPs for drifting, New Tune, perrin pulley, Oil cooler, new brakes and rotors, GT86 headlights, TOMs tail lights, some other cosmectic nonsense like Toyota badges.
Not the most original list, but I want to keep the car NA, mostly for reliabilty reasons.