The side mirrors on a Mercedes vehicle, such as the 1985 to 1995 E Class, utilise large mirror housings that bolt completely through the side of the door and bolt from the inside door panel. This is common for many other late model vehicles. Since the mirror does not bolt to the sheet metal on the door, you do not have to remove the glass window to repair a loose side mirror on your Mercedes.
Locate the cover that hides the wiring harnesses and the nuts that secure the mirror to the door. It is triangular in shape, located on the inside door panel, and secures to the inside of the door opposite where the mirror housing secures to the outside of the door.
Pull the panel off the inner door by grasping it with your hands and then by pulling outward on it.There are plastic tabs that fit into holes in the inner door panel. As you pull on the panel, it will free the tabs from the inner door without damage.
Tighten the three bolts located behind the cover with a deep-well socket and a ratchet.
Place the cover back onto the inner door and push on it with your hands. The tabs on the back of the cover will push into holes in the inner door to secure the cover to the door.