This is Jason, the guy that bought Joey's TOP Rebel... As, probably, the most recent person to have "the novice experience" at CORRC, I thought I might chime in.
Have you guys looked around the pits? You are all engineers, IT guys, electronics hobbyists... maybe you ought to be throwing up flyers in your local business parks or wherever those folk hang out in your area. You've got Sparkfun right up the road in Boulder and they are having the 3rd Annual Autonomous Vehicle Competition in there parking lot on June 16th. You guys should DEFINITELY have flyers there.
I wouldn't rule out MHOR, either. I started in off-road because that's what I had available. Once your in the hobby and know that you enjoy it and revel in the occasional frustrations, you start to look around at other facets of the hobby. Short Course is just a gateway drug. There is no reason CORRC can't be their boutique narcotic. Granted most off-road guys are going to explore rock crawling before on-road, but not all of them. Give it a shot.
Speaking of Short Course... F1 IS your Short Course. When I walked in there I was really hoping to see some F1. It just looked really cool from a total noob point of view. You guys should really do what you can to get that class going. It is the most interesting to people, like me, that walk in without a clue.
Loaners. If you guys have some clapped out TC laying around, a spare 17.5, Clegg's $50 MX3, keep it at the track. When somebody walks in, say "Here. Give it a go." A couple laps is all they'll need to get hooked on on-road.
You guys have a great program going there. You just need a little exposure in the right places.