In DC/MARRS, Spec RX-7 (no IT-7) was started by Bret DePedro, a long time RX-7 driver and shop owner. Whether or not his motivations were fiscal is irrelevant, he has run the class well for the past 4-5 years. He's prepared a good number of the cars, but they are so easy to build that many are home-developed or done by other shops. The rules have administative tasks/duties outlined, so there are yearly elections for class admin, rules changes, etc (requiring 75% approval to pass, which rarely happens).
The class started running with 5 or so cars in the ITB group, then grew and moved to the ITC group. Last year, it got large enough to have a seperate run group. This year, attendance is 37+ avg and 51+ max.