If your going to drive fast your 1st mod should be BRAKE upgrade, eather Big Brake Kit or Rotors, Pads and Stainles Steel brake lines. Yestoday I took my car to canyons and almost crashed, I would say get brake upgrade
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If I would do the car again I would do
1) Brakes ( Rotora or Stoptech with 4 piston BBK )
2) Suspension ( Tein SS or BudyClub N+ or Skunk2 Pro-S )
3) Sway Bar ( H&R front and rear sway bar or Progress)
4) Wheels and Tires ( Tires - Nitto NT05 )
5) Intake ( CT Engineerings - Ice Box or Injen MR )
6) Headers ( Hytech or CT Engineering )
than high flow cat, catback exhoust, reflash and so on. For me handling is more important than extra 50hp