I took my 2001 4.4i X5 w/ sports package to the dealership to get the wheels aligned because the very inside 3/4 inch of my tires where burning off while the outside looked absolutely untouched. BMW (Bavaria BMW in Edmonton, AB) said that they aligned it to spec (which wasn't much of an adjustment) but it continues to wear out the rubber on the inside. They also said that it could be a worn out part but couldn't tell what specifically was worn so they offered to to start putting new parts in piece by piece at my expense to see if anything helped but couldn't guarantee me that anything would work... this didn't instill any confidence in me from these guys.

I looked on bavauto.com for this rear camber kit but only could find a camber kit for the front.

I know lots of people have had the same issue but has anyone ever fixed this problem? Speculation is not helpful.
I'm considering selling it because it's too expensive to put a new set of tires on every year just to wear out the inner 3/4 inch and leave the rest of the tire virtually untouched.