SCCA 2013 Solo (autocross) rules:
3.3.2 Roll baRs
Roll bars or roll cages are strongly recommended in all cars. A roll bar meeting the requirements of Appendix C or a roll cage meeting the requirements of the Club Racing General Competition Rules (GCR) (Section 9.4, Roll Cages For GT And Production Based Cars or Sec- tion 9.4.5, Roll Cages For Formula Cars and Sports Racing Cars) is required in all A Modified (AM), B Modified (BM), C Modified (CM), and F Modified (FM) vehicles and all open cars in Prepared Category, D Modified (DM) class, and E Modified (EM) class. For open cars in the Stock, Street Prepared, Street Touring, and Street Modified categories, the roll bar or roll cage height may be reduced from Appendix C or GCR 9.4 requirements to the highest possible height which fits within an in- stalled factory-specified hardtop or convertible top. The roll bar or roll cage height may also be reduced in the same manner for cars in the Prepared category with a full original equipment windshield assembly and a standard (as defined herein) hardtop which has been bolted se- curely in place.
Double-hoop roll bars must fasten properly to the chassis/unibody as required by Appendix C, particularly at attachment points in the center of the car.
, Rich..and everyone else
