I recently ran my first club race, albeit with NASA and not BMW CCA. Nevertheless, I will choose a class for the car in both NASA and BMW CCA over the winter, and will finish the car to that class. For now, it stumbles into KP with BMW and GTS with NASA. The big question for me is whether or not to "detune" it for SpecE30, which is a NASA series growing in both popularity and publicity (CCA has recently indicated they are looking to recognize it as well).
You can read a write-up on the race experience and watch the whole race at:
http://axisofoversteer.blogspot.com
Or, if you want to go straight to the video, you can find it at:
http://www.youtube.com/watch?v=urrcTWabrEw