Welcome to the board Jeff! Autocross is fun as hell. I did it for a couple of season in a 97 Camry. Here is a hand book for Solo2 It will answer alot of questions you might have.

http://www.tirerack.com/features/solo2/handbook.htm

What class are you planning to run in? I was in the STS class. as for mods, beef up your suspension, Strut bar, sway bars, Springs and struts, or you can go the extra mile and do coilovers.

 

I'm not to sure about the classes?

 

Depending on what mods you have done to your car, you will be put in a certain calss, anywhere from stock to track. If you read the hand book(the link I gave) it should answer all of you questions.