if you are new to the game, i'd strongly reccomend staying in a stock class. with a gsr you will be put into D-stock, which is already pretty competitive, you will be running with just about every non-m3 bmw that shows up, audi s4's, dodge srt-4's and things of that nature. anyways, in your stock class, SCCA solo 2 rules allow things like cold air intakes, catback exhausts, short throw shifters (which are actually worse for autocross), and any type of seat/harness combinations you want. as for suspension/handling items they allow adjustable dampers (shocks) any tire you want on the stock or stock size rim (including r-compound slicks) and thats really about it. the minute you do any chassis bracing like stut tower bars, or bigger sway bars your bumped to a street touring class which is much more competitive. also, any lowering of the car, including race springs and coilovers, will put you into street touring or street mod classes depending on exactly what is done. so if you want to stay in stock, which is a good idea for learning and you'll do better in your class, go with a set of adjustables like koni yellows or kyb agx's, and get a set of nice tires, something thats summer only made for grip on pavement, like a set of falken azenis (best tire for the price hands down, awesome grip and can be driven on the street). the rest is basically a matter of practice and experience, have fun with it. most fun you can have with 30 dollars and a helmet.