Just out of curiosity, do the Z4M's have a 2-stage traction control? I only turned off the DSC, but kept the DTC on. This allowed some slip, and the computer wouldn't cut throttle too soon.
Anyway, I didn't get a chance to meet anyone except Mark (not sure if you're on here), but I was in the white E92 335i. I put together couple videos from Laguna Seca.
Highlight video:
My quickest lap of that day: