Performance upgrades for new autocrosser

Driving a 2003 325i - what would be the most effective performance upgrades in order of importance to optimize my autocrossing experience?

A driving school :
http://www.evoschool.com/

Once *you* get faster, then everything falls into place. It will be the best return for the dollar for a "performance upgrade."

Indeed - your local BMWCCA chapter might very well be hosting a driving school or two - check your chapter's website for what's going on.

Forcing yourself to keep your eyes ahead of the car on the course will help, look as far ahead as you reasonably can (without taking out cones). That takes some practice and getting used to, as things are happening so fast with so many changes of direction in a short time.

Biggest thing you can change - tires. After that, whatever you spend/modify will likely yield changes and improved course times, but less dramatically.

i agree completely- schools are the best performance upgrade u can make!!! modding the nut behind the wheel. i attended our local bmwcca chapter car control school and learned a ton when i first started out! it was a bargain based upon what i got out of it and skills i was taught helped me become a safer driver on the street. the evo school is a great investment also- it's truly an autox school rather than just a car control and safety school. good luck to you!

Like Cat said, the nut behind the wheel makes the biggest difference. If you don't believe that, have a really good autocrosser drive your car and then compare their times to yours. It's a very humbling experience.

Get more experience first....then get a set of r compound tires and lightweight wheels. That's where you're going to see a couple second decrease in lap times....IMHO.

Yup. Experience. While a high speed school is very good, the car control schools many chapters offer are more valuable for autocross. Getting off course on a track is cause for a black flag, but getting off course on a car control skidpad is expected. Race trained drivers find it harder to move to autocross than do autocrossers moving into track driving. The reason is simple. In autocross, although you may be going slower, things happen faster. I would wait at least one season to think about making any changes to your car except tire pressures. Learn what you're doing and how your driving challenges your car (probably not much yet) before raising its capabilities beyond your own. Whenever I am asked to offer a goal to driving students, it's this:

Raise your own ability to the level where you can safely and reliably (repeatably) exceed your car's capabilities by a slight amount. Then you can look at raising the parameters you can exceed. IOW, if you cannot slide the tires on which you're driving, you don't need better tires. You need to get better yourself.