The MC was started on the west coast a couple of seasons ago and has since spread to a few different regions in the US. The west coast and Texas, as far as I can tell, are the two most active areas.
That said, for those that do not visit the typical Miata forums, the MC is a fairly open set of rules for time trial events. There are only 3 classes, and each are based on points. The points vary for different types of modifications, but these are some of my favorites:
Other:
Excessive Rice +1
Non male -1
Automatic Trans (Miata engine only) -1
Rental Miata/MX5 (with rental contract) -1
I haven't paid much attention to the MC until recently. Seems like this could be an extra level of competition and fun for the many Miatas that run with us. There are currently no time trial clubs in the Northeast that run the MC, so there is the possibility of a bit more exposure for COM, especially at our away events.
The MC would run concurrent with COM events. Other than handing in an "entry slip" and potentially having their Miatas checked for proper MC classification, MC participants would not have to do anything different at COM events. COM's official Time Trial results would be used as the MC competition results.
If there is interest, there would have to be a handful of volunteers interested in helping out at the event. Keep in mind that this is totally separate from COM rules and such. That said, the workload should be very minimal, and there is likely only need for a single MC volunteer at each event.
I would be wiling to help get this off the ground, but cannot commit much time to the effort, as my plate is already full...
The 2010 MC rules can be found here: http://forum.miata.net/vb/showthread.php?t=360170
But God forbid I spend money on the Subaru 
