is it rear door or front door? on my 300e the rear door bulb is easy to get out if you remove the ashtray and the plastic around the ashtray. I never tried, but you could probably get to the front bulbs by moving or removing the storage compartment at the base of the door. Your problem may also be with the wiring snaked through the rubber tubing that sits in between the door and the body. This gets worn down and broken after years of door opening/closing. Good luck.

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headrivenoise... listen.