Cardboard: I go to SouthShore Hobbies Raceway in Coram, NY. It's one of the best carpet race facilities in the east coast. They are holding the regionals in Oct.
Come on down some day. Check out the schedule at:
www.southshorehobby.com 
Thanks James N. for the input. Going to put some serious testing tomorrow night. That day can't come fast enough
