Hey folks, I went to the SF event as well and here are my thoughts.
I have never autocrossed before and it was a blast. The instruction was decent, perfect for a newbie like me. It was fun to bang on all the Mazda vehicles. I got to drive several 6's a Miata MX-5 LS (I think, it was the one with the 6 speed), and the 2003.5 Mazdaspeed through a slalom course with Falken tires. Entertaining and well worth the $40.
The only problem is they got WAY behind on their run times. My first run on the track was scheduled for 3:20, I didn't get on the ccourse until 5:10, very frustrating. So if you sign-up sign up for as early a slot as you can. As a result of the delay I left before my second run on the competition course. I had been there since 11:45 and didn't want to wait around any longer.
All in all the event gets two thumbs up from me, aside from the delay in run times it was a good experience and driving the 2003.5 Mazdaspeed was really a pleasent surprise. I am wishing now more then ever that I hadn't gotten the auto with my protege5, never thought driving could be this much fun after spending most of the last several years driving a nissan pickup. That is one mistake I will not repeat.