Going to my first auto-cross, in the RX-7, what do I need to know?

[P71]

So I've been filling out forms all week, I have my SCCA membership sent in, and the paperwork for the auto-cross. It's a Novice only event (maximum limit of 10 auto-crosses to be allowed into this one). It's in exactly 30 days.

I already have a Snell M2005 full-face helmet (for drag racing) and the car itself is my 100% stock 83 RX-7 GSL which has a fresh tune-up and oil change.

What else do I need to do, especially to the car, before the auto-cross? I'm not worried about winning or placing, but seeing as how it's a 50-mile drive each way to the event, I'd like to finish the event and be able to drive home with no problems.

My car does have new tires and runs and drives well. It does have a bizarre groan when turning very tightly and/or going over a bump/dip funnily (like at an angle instead of straight on). It's manual steering and the posi works excellent. Brakes seem very good, but I haven't actually had the wheels off to check.

Any and all advice is appreciated. I just want to be able to concentrate on the instructors and learning how to auto-cross properly without worrying whether or not the car will make it!