For a 1999 Mercury Sable wagon : I believe you will find the six disc CD changer ( if equipped ) in the cargo area behind the panel for the storage compartment / service compartment on the right side
I found it behind the fuse box in the glove compartment. Take off the glove compartment cable on the right side, then remove the 4 screws for the fuse box. It should be right behind the wiring.
remove glove box. disconnect harnesses and remove evaporator and thermostat is behind it. remove glove box. disconnect harnesses and remove evaporator and thermostat is behind it.
Part of the relays are located in a battery box at passenger side floor, and the other relays are located on a firewall (engine compartment) behind a black plastic cover under a few wiring harnesses.
On a C-Class 1994-2000, you don't actually change the headlights, just the bulbs. They are located on the inside of the engine compartment. They fit easily into little harnesses, just behind the headlights.
2002 cabrio CD changer plugif its the same as the 2000 cabrio, its a ten pin plug behind the right hand tail light in the trunk It's just below the right side tail light assembly, door lock servo motor (which is wrapped in styrofoam) should be plugged into a dummy socket just above trunk floor. It's labled CD Changer.
If your x5 is equipped with a CD changer, it will be located behind the driver's side panel in the very back. This is not standard equipment, however.
In the trunk on the passenger side behind the panel for the CD changer.
the firewall is between the passanger compartment, behind the dashboard and the engine compartment.
in the engine compartment below the dashboard and behind the glove compartment
IT is behind the little pull our compartment on the left side of steering column on the dash. Pull out the little compartment and the fuses are behind it.
right hand side of the steering wheel behind the little storage compartment, its behind that undo the four screws and the compartment will pop out, the fuse map is on the back of the compartment.