This Sunday there is an autocross, but it's full for participants (with a healthy waitlist as well). Spectators are more than welcome though!!
There's
another autocross event on October 12th that is just barely full, and if you signed up, you'd likely make it in, after a handful of people cancel.
I'm certainly biased, as I chair the events with my friend Christo, but I think they are incredibly fun, and worth the cost of BMW CCA membership ten fold.