Like I said, I'm totally new to Autocrossing. I only know about it from reading about it here in this forum.
On 7/10 and 7/17 @ FedEx Field they're having some SCCA solo days and I'm pretty interested in trying it out. I'm in a stock 2005 GT except for CAI and tune and axlebacks. I'm toying around doing it in my stock 2003 Saturn ION-3 only because 1) I've had that since day 1; 2) it's lighter; and 3) I've only had my Mustang since April. I just know how my Saturn handles since it has been my DD for 8 years.
I understand that they do a walk through of the course, especially for novices, but how are the courses? Each place is different and each course is different each time they have an event, I understand that. I have looked up youtube and it seems that it's a mix of slalom, tight turns, high speed lane changes, and short straights. Does that seem to be a good generalization of what a course might look like?
On the 10th, I'm taking the Saturn and I MIGHT give it a go. If it looks fun and/or I actually run it and have fun, I'm thinking of taking the Stang on the 17th.
I don't expect to break any course records or even place in the top 10 of my class, but from what I've seen, this appeals to me more than Drag or Circle racing.
Take the 'stang, trust me, she'll run! I ran my first event on the 12th of this month. Course looked like:
Mix of slaloms, lane changes, etc. My tips:
1.) Figure out what class you are in. The CAI will pull you out of F-Stock and probably put you in Street Touring. Go look at the rules and see what you can run.
2.) Arrive early. This allows you a couple of things: It will allow you to talk to other drivers, it will allow you to get your tech inspection out of the way when it's not frantic, and it gives you plenty of time to walk the course BEFORE the Novice walk.
3.) Walk the course, a lot. Generally they split the day in half. Each half is called a heat, while one heat is running, the other is working. Between heats they have a break. If you are in the second heat, WALK THE COURSE. I walked the course 4 times during the day. Twice before the Novice walk, the Novice walk, then in between heats as I was in the second heat. Most importantly in the walk, walk the course like you would drive it. If there is a slalom, don't just say "yeah, it's a slalom" and walk on, actually walk the slalom, cut the corners like you would in the car, then go wide if you have to, etc. Try and memorize the course.
4.) Bring sunscreen and USE IT. Apply often or Lobster-itis will ensue.
5.) Bring a tire pressure gauge. Keep track of the air in your tires. As you run the course the tires will heat up. I'm not sure what tires you have on your GT, but I have the KDWS on mine and it was fairly easy to tell where the pressure needed to be at depending on where the "wear" line was on the tread. Lower the pressure so it gets close to using all of the tread in corners. Better yet, don't mess with the pressure, just keep it constant at the recommended running temperature.
6.) Talk to other drivers. Especially talk to other drivers of Mustangs. There will be a lot of them I promise

I had the privilege of speaking with Don Knop, a national champion in F-Stock. He gave me some good tips
7.) Empty your car out except the Spare Tire and it's hardware. Pull the floor mats, stuff in the cup holders, anything that is loose. Also clean the car (looks good for the pictures and makes you feel better about the car

). I left my spare tire in my car. The weight in the back end will be important!
8.) Take the first run "easy" and get more aggressive as you approach the last run.
9.) MOST IMPORTANTLY HAVE FUN! Dead serious, HAVE FUN. Meet some new friends, and talk with people. Ask questions about tire pressure, about tire selection, about class rules (if you have any questions), watch how others take their corners and run the course, but HAVE FUN.
It's an addicting hobby! Once you get hooked, you will need to set a goal for the class you plan on running your car in. Be it Street touring, street prepared, Street mod, prepared, whatever, and build your car to that class. Don't build yourself out of the competition by adding something that knocks you into a more aggressive class than you are capable. I'm not saying you wont have fun, but it's not as much fun when you see yourself last in your class!!!!
As for driving tips: The S197 is a good platform when driven hard. It is not without it's faults. Two things to watch out for: Plowing during breaking and cornering. Better to enter the corner slow then to break late and plow through a cone or DNF by failing an obstacle. Lastly, Oversteer. You will most likely be in second gear the entire time, and generally right around the 4000 RPM range which puts you right where the 4.6L 3v has a ton of torque. It is very easy to get the rear end to come out with stock tires. Street tires communicate VERY WELL when traction is about to be lost, and you need to hear the squealing of the tires while cornering to find that limit of when they will and wont and run at that ragged edge all day, but don't push it so far that the back end comes out and you lose control. You will know that limit and if you do lose control, better at an AutoX event then on the street!
Also, don't be surprised if after the first run you are shaking. I was, and BAD. It was a good and hard shake for me, and god it was amazing. I'm already jonesing for the next event on the 24th of July. It's so far away =(