Originally Posted by Macho Toy
So can a VIN determine the original diff in a car? If so, can someone at a dealership tell me otherwise?
Yes. Whoever dealt with your, doesn't know what he/she was talking about. Here is your build sheet straight from the BMW servers.
By the way, do not waste your money buying fluids at a dealer. Go to either Canadian Tire, Napa or Parts Source and get a synthetic 75W140 gear oil that is approved for LSD.