[radroach]

Doing just intake, catted frontpipe, and overpipe / downpipe, and 93 or e85 tune is all you need to get a really good performance without changing much of the emissions aspects of the car. Recommend you check out Perrin's product pages here. Been in a tuned car with these mods and it was plenty powerful, sounded awesome with the perrin CAI.

Headers are the next step to get full modded exhaust setup, but you'll likely sacrifice emissions, and they're usually much louder than the stock headers.