A very common Fox Mustang failure is the Door Hinge. 9 times out of 10 the failure can be repaired by simply replacing the Mustang Door Hinge Pin & Bushings. However, sometimes the damage to the hinge is so severe that a full on Dooe Hinge replacement is the only option. Another common problem is a missing Mustang Lower Door Hinge Roller. The Lower Door Hinge Roller helps keep the door from closing when in the full open position.