If you have the original front control arm bushings at 80k, you're probably due for new ones. I have seen DIYs posted here recently, quite easy to do yourself. A visual inspection is valid, but replacing them anyway is a good thing to do at that mileage. If they're just ugly and not making any weird handling or noises, then they won't ruin your fun.
Springs and shocks should be OK for another 10k-20k miles, then shocks likely. You can inspect them for leaks now. Even if they are leaking, they won't prevent you from enjoying your first autocross experience either.
Check the rear shock mount at the top, inside trunk, under trim panels on either side. They are prone to premature failure. There are upgraded parts available from some tuner sites (bimmerworld, turner, etc) that are much more beefy and very simple to install. In fact, if you're going to inspect them, you may as well order new ones and just replace them while you're in there looking at them. Getting access is most of the hassle.
Check the rear swaybar bushing mounts, they can fail. I've had mine beefed up cuz I beat, er, use my car for it's intended purpose. No issues even with 30+ track days and 15 or so autocrosses. I had it at a shop for some welding work and just had them do it while it was there.
I highly recommend the Sock Mod to prevent your p/s reservoir from spewing all over your nice clean engine. Check the level and make sure it's correct, if low, add ATF to top it off. If you don't know the history of it, change it. DIYs around for that too.
http://www.youtube.com/watch?v=_1pzRJMwRx0
Other than those things... if your car is driving fine and not making any weird clanking noises, you should be good to go. Be sure to torque lug bolts when you get to the event. If you don't have a torque wrench, someone around you certainly will. Make sure to pump up your tires some, 38-40psi. Stock suspension has very little negative camber up front and you'll roll over the sidewall of your tires if the pressure is too low. You can ask others with similar car/tires what they run and adjust yours. I like to show up with too much air and let some out... that way I don't have to dink around with a pump to add air, easier to remove it.
Your engine may tick (lifters) after a few runs, but it will go away on the drive home. Top up the motor oil so it's at or just above the full line. It's OK to run a little more. Even tho I do this, mine still ticks... it's a feature of the E36 and E46 and freaks out first timers. It's normal.