Awesome event with SpeedSF as usual. The rain adds a new element in planning for the shot. I end up picking the straight uphill after turn 6 because you are going full throttle up against the rain and has a nice rooster tail. Here's something I tried from farthest to closest panning shot in the rain.
Inside corkscrew is another good place to capture the effects of the rain, but, understandably, most people are more cautious and don't drive too close to the berm.