I was lucky enough to see the GT series at Laguna Seca a little while back. The GT3 and GT4 cars race simultaneously so there is a ton of action all the time. Being across from the pits in the grandstands was great...pit stops for tires are pretty crazy (although not as fast as F1). If you drive a GT, you should make it to one of these races to see how your car can really be driven!