NASA is running a race weekend at PPIR over Labor Day:
http://www.nasarockymountain.com/nasa_forums/showthread.php?t=2269
In-car video (from the “old days”) of a 944 on track:
http://www.whapp.com/sm/ppir_944_may2003.mpg
BIG video (you’ll want to right-click and download) of an SRT4:
http://www.whapp.com/sm/SnymoITESRT4Highlights.wmv
HPR does sound more kart-friendly, and when I talked with some of the local SCCA folks last winter they seemed pretty eager to develop better relationships with the karting community. I think NASA is all tin-top racing, but if people want to stay in open-wheel, SCCA is certainly one option.