Comand Screen not working
The most important thing to know is are the rear DVD screens factory units or aftermarket jury-rigs? You said rear DVD screen so perhaps you have the Mercedes aftermarket unit that mounts to the rear of the front console?
The head units sometimes come up for sale on ebay. You probably don't want to know what they cost at the dealer. I've heard rumours of the newer ones going for 4 or 5 thousand.






