Just took delivery of a 2011 750 Li Xdrive sport. Leaving the dealership with 10 miles on the odometer, I turned a corner - stepped on the gas and heard a loud clang and felt the rear end shudder. Straight driving was OK, but turning reproduced the same problem. Back to the dealership where a differential failure was diagnosed. Supposedly a bulletin was issued for some new 5's that had a similar problem. This was a new finding with the 7 series. New differential was to be 2 day air freighted from Germany. That was a week ago. Dealership reported another unit in receiving at Baltimore with the same problem. Has anyone had a similar experience? Dealership repair people state a bad weld is the culprit. Wonder how extensive the problem really is.