Just attended the one-day "Phase I" class at evolution Performance Driving School and I was very impressed.

http://autocross.com/evolution/

The instructors for the day were Darrin Disimo and Bruce Bellom (both very nice, very professional, and very fast). The class was on Long Island, but goes all over the country - see their calendar

The Phase I course is a short, complex affair which tests a whole lotta skills (About a 32 sec course for a fast S2K driver - broken into 5 timing segments). I was able to shave 2 seconds off my time by the end of the day

Bear in mind, I've only AutoX'd 3 times, so more experienced racers attending didn't get as dramatic improvements, but EVERYONE improved!

Also - small groups (12 students), and lots of seat time.

Best $200 you can spend on your "car"!