http://www.clublexus.com/forums/is-f/392055-official-is-f-modification-thread.html
Performance wise:
Sikky Headers
Elite Headers
Joe Z Exhaust
ISS Forged Exhaust
Elite Ported Intake Manifold/Throttle Body
Joe Z Intake/AFE Filter
Takeda/Injen/K&N Intake
People are working on tuning software and a supercharger kit is in the works by elite.
Performance wise:
Sikky Headers
Elite Headers
Joe Z Exhaust
ISS Forged Exhaust
Elite Ported Intake Manifold/Throttle Body
Joe Z Intake/AFE Filter
Takeda/Injen/K&N Intake
People are working on tuning software and a supercharger kit is in the works by elite.