A. Production-chassis cars: The roll cage must attach to the vehicle structure within the passenger compartment in a minimum of six (6) points as specified in these Rules.

B. Tube-frame cars: The roll cage shall be integrated into the frame or chassis.

C. Mounting Plates

1. Mounting plates welded to the structure of the car shall not be less than 0.080 inches thick and no more than 0.25 inch thick. Plates may be on multiple planes.

2. The thickness of mounting plates bolted or riveted to the structure of the car must not be less than the thickness of the roll hoop or brace that they attach to the chassis and must be backed up with a plate of equal size and thickness on the opposite side of the chassis panel. Plates may be on multiple planes but shall not be greater than 15 inches on any side.

3. Fasteners for bolted or riveted mounting plates must be Grade 5/Metric 8.8 or better with a minimum diameter of 5/16 inch.