I installed a 4-point (just autocrossing, no road racing) in my Bullitt. I attached the shoulder belts to the rear seat belt mounts (under the rear seat). The shoulder belts on mine have an H-strap that keeps the two belts close together, joining them right behind the headrest, so they don't slide off to the side. I mounted the seat belts to the same mounts as the stock belts (keeping the stock belts installed for daily driving). I had to saw off a small steel lip on the inside belt mounting bracket that interfered with the racing belt eyelet. Otherwise, the install was easy.