I went to a race last weekend at New Jersey Motorsports Park I was the only one running a Mini.
Clearly, you need to move about 600 miles south of Pottstown.
We flew in for the weekend, and even with all the rain (and the rained out TCS event) there were two FULL HEATS of Mini's that rain in the short, non-rainy, non-TCS event from late morning through early afternoon.