Left Upper. Left.DRIVER SIDE. Lower hinge nut. A solid metal or plastic block with a threaded hole in the center which is used to tighten or adjust the Exhaust System Hanger. Nut that fastens the door Hinge to the vehicle. Window Regulator Nut. SPECIAL. Center mount. Door. Exhaust System Hanger. Lock. Retainer. Ring. Window Regulator.