51 22 004 Adjusting rear left or right door detent (lock wedges)
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2010 BMW 528xi, 2010 BMW 528i, 2009 BMW 528xi, 2009 BMW 528i, and 2008 BMW 528xi. However, it is still accessible from the selected car via links, so may be relevant.
Operation is described in: Adjusting left or right rear door.