Im with ic3b3rg, tighten up the nut between the wheel and the seat. HP Drivers Ed goes a long way towards making you a better driver.
If you still on the stock all seasons they are great on the road but not stellar on the track. Swapping out for more aggressive summer performance compound can really unleash the car.
I also recommend following a suspension, Brakes, then power route when upgrading. Even simple things like poly suspension bushings and stainless brake lines make a hell of a difference. The 16 has much tighter factory suspension but it can do with a poly bushing/swaybar/endlink upgrade. You might also want to look into performance brake compounds if your spending time at an track where you need that extra performance.
If your looking for more options to add power after the inter cooler your getting into more aggressive tune area. To support the more agressive tunes you should consider 1 step colder plugs, then maybe swap your fuel delivery system with something capable of running E85 or you could add a methanol injection system. Both of those are really just ways to allow your tuner to be more aggressive without undue strain on the engine in the form of knock.
Speaking of aggressive tuning what company is handling your tunes at the moment? if your still on the Cobb OTS tunes there is quite a bit to be gained from working with a professional tuner or a reputable E tuner like Eric from Torqued.
hope that helps
Slow is Smooth > Smooth is Fast