Alex, on our MB vehicles the brake lights don't work unless the key is in position 1 or the car is running. To replace the center brake lamp use 2 small screwdrivers to simultaneously lift the tab on each side of the plastic housing and slide the housing forward. Be careful not to apply too much pressure to the tabs or you will break them off. Replace the lamp with an Osram/Sylvania European lamp of the same wattage and slide the housing back into place until the tabs latch. The Owner's Manual should list the proper lamp or call your local MB dealer. Pep Boys sells the European replacement lamps ... less expensive than dealer prices.

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Fred Hoelzle