Interiors may be gutted, cams and pistons are free, and suspensions may be significantly modified. Cars prepared to Road Racing GT and Production rules are permitted to run in Prepared. The Modified category is split into parts. D and E Modified are for very heavily modified production cars. D Modified is for cars with engines less than 2 liters, and E Modified is for cars with engines greater than 2 liters.
Most clubs offer a separate class in which women can compete in addition to the overall competition.
This is signified by the letter L being added to the classification on the car. For example, CSP-L . Again, most clubs offer a separate class in which newcomers can compete in addition to the overall competition. This is signified by the letter N being added to the classification on the car. For example, FS-N .