I’m currently in litigation with a repair shop which botched an oil change on my 2003 E55 and ultimately caused the engine to seize (snapped off the oil filter housing shaft). Long story short, I need to prove to the courts that they were in fact the ones who performed the oil change (they are flat out lying saying they never touched it).... Does the “workshop code” noted in the ECU’s service history have any connection with the specific shop which would have reset the service interval? (see attached photo):

 

The workshop codes are described in the service book for most Mercedes cars, I think it's the same for e55. I can have a look in mine once I get home. Mine is EU though but it should be the same.