Rebuilt both of my wife's tail lamp assemblies. She reported "a light icon showed up on dash behind car diagram". I said probably brake light out and she had a friend operate the lights to confirm
Today went to pick up some new lamps and the store had some led equivalents for a very decent price so I decided to try them
Managed to drop the lamp holder behind/beneath the SUBWOOFER! Holy crap. Can't even get my goose neck inspection camera in to see where it landed. Can't remove sub without removing the fuse holder aargh! Ended up needing to remove the plastic subfloor of the cargo area to retrieve.
The lamp assemblies both self destructed. I'd be willing to bet an eventual occurrence in a majority of e53s. What happens is the contact gets a little dirty and when the resistance rises the power drop on the bad contact heats up the metal strip to the point it softens the plastic supporting it and the metal contact pulls away from the lamp holder. The problem gets worse exponentially and burns the contact point on the metal as well as melting the plastic holding it.
Google repair x5 brake lamp assembly you'll see quite a lot about it.
The metal is supposed to be at the same level. It's about 1/8 inch low in front.
After the fix. Better than new.
After fixing the starboard side I of course checked out the port side and was just about as bad so fixed that one as well.
Since we have identical year and model e53 2001 my wife and I, I of course checked out mine as well but my copy of the car has replacement tail lamp assemblies made in 2012 and BMW made the contact force about 40x as hard to eliminate the problem.