Seemed like a good idea at the time? ::shrug::
I think it will end up being a successful class. There are several cool cars in there, and the price spectrum ranges from mild (ten-yeard old C5 Vettes) to semi-wild ('08 Cayman S, E92 M3, 40th Anniversary 996 911). If I were shopping for a new autocross car, an A Stock car would be high on my list... right behind something for STR, which I think is part of the problem.
I will say I am a bit surprised that we haven't seen more cars show up yet.