WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Side Wall (0493779)
Courtesy of BMW OF NORTH AMERICA, INC.
NOTE:
(side wall) Left side wall. Only required once to set up the base frame, discontinued, available as part of set of special tools only