I should have typed not limited slip instead of non-slip. Thanks for pointing that out as that could have confused future readers.

Anyway, there's no BMW dealer that sells the diff fluid but I found out that BMW and Land Rover used to share parts in the early 2000s, which is how I found out that the diffy fluid is the same but only sold at LR dealers! Crazy.

Thx to everyone that helped on this thread.

BTW: I found the 14mm hex socket at Pep Boys for $12, came w/ a 12mm and 17mm also in 1 package.