Autopower - E92 M3 Roll BarE92 M3 Race Roll Bar *Shipping Included in Pricing* The race roll bar is designed for solo, autocross and high speed time trials. All Race roll bars have a diagonal cross brace and most have a harness mount tube. Autopower will select tube size and type for your needs. Race roll bars are made with 1. 750 x . 120 DOM steel. Cars weighing more than 3500 lbs. use 2" x 120 ERW steel. 4 point mounting with welded diagonal cross brace. All necessary