If you haven't spent a lot of time around SCCA (and SCCA clone) autocross clubs, figuring out where your car belongs can be pretty tough. I hope that by writing a guide just for Miata classification, I can make it a bit easier to figure out where your car belongs. I'll also stop short of discussing Modified and Prepared classes.

In the SCCA classification system there is a hierarchy based on car preparedness level. Stock classes allow minimal changes from the way the car left the factory (not the showroom). Street Prepared classes allow a lot more modifications while retaining interior trim. Prepared and Modified classes allow full race car preparation.

In recent years, two new options have crept up. Street Modified 2 (SM2) allows lots of "street tuning" modifications like engine swaps, forced induction, etc. This year, STS2 (Street Touring 2 Seater) became available as a class for some Miatas. This class allows many of the popular Street Prepared mods, but requires "street" tires.

If you bought your car new and haven't changed any parts, you can quit reading now. '90-'93 model year Miatas run in E Stock, '94+ Miatas (except the Mazdaspeed) run in C Stock, and the Mazdaspeed MX-5 runs in B Stock.

All Miatas are eligible for Street Prepared category. The Mazdaspeed runs in BSP while all others are in CSP. A fully prepared Spec Miata (with logbook) may enter in DSP.

If you've made some modifications, you'll need to check the chart for legality. This chart is not complete, but rather intended to address the most common mods. Remember that SCCA rules state that "if the rules don't address it, it's not allowed." If you can't find your modification here, check an SCCA handbook. If it's not there, it's not legal.