I'm not an expert, but I've been doing autocross events for 15 years, so I'd like to think I know quite a bit. If we are talking about SCCA autocrossing, there are a few things you can do in stock class. You can run any air filter element, spark plugs/wires, and catback exhaust. For suspension, you can run any stock-type shocks with stock springs, change the front or rear sway bar (but not both), and run any DOT approved tire that fits on a stock size wheel. If you go above these changes, it will put you into a different class where the car may or may not be competitive. Let me know if you have any questions.
so im going to be kinda prejudiced but im assuming you know alot about AutoX? im looking for some help about what takes you out of a class? like from stock class? i heard u could do some stuff
Friends 
