Good stuff, I hope you stick with it. The best advice I can give you can be summed up fairly quickly:
1) Dont go crazy with upgrades. Get yourself another set of wheels, a set of Hoosier A6's. Thats the only thing you really should do right now. If you get serious about autocross, you're going to want to use a different vehicle, so dont pour tons of cash into what you have now.
2) Keep your head up. You need to look as far through the course as you can, keep your head and eyes up, rotate your head, look through corners instead of at them. You can see in this video, how much I'm turning my head on one of the huge sweepers, as it required me to see through the exit and use the throttle to set up everything (
http://www.youtube.com/watch?v=Efn5TxXtrTo ).
3) Keep your head up (in a different way). You're going to get kicked in the teeth by your competition, everyone is bad at first. Doing tip 2 will help with tip 3. Learning to drive is a growth process, dont worry about how you're doing vs so-and-so. The only thing you should be worrying about is if you're becoming more confident with your driving and learning how to read the course well. If you cant beat the course, you cant beat anyone.
4) Ask questions and walk with fast people. Dont bug them on their course walk unless you know them well, but just walk beside them or behind them. Copy the line they walk, see what they see.
5) Stay ahead of the course. Kinda goes hand in hand with tip 2. When you enter a slalom, make sure you can backside that first cone and not get behind on it. You can see in this video (
http://www.youtube.com/watch?v=oEXv9jRbUd4 ), I'm not late on sections, I'm constantly looking ahead and turning in to setup for the next element.
If you have questions, feel free to ask me, I'm an open book. I autocross nationally all over the country and have done and seen a lot. If I dont know the answer to a question, I'm certain I know someone who does =)