WARNING: This page is about a different car, the 2013 BMW X5 M, 2012 BMW X5 M, 2011 BMW X5 M, and 2010 BMW X5 M. However, it is still accessible from the selected car via links, so may be relevant.
View from below.
Open spot-welded adhesive joints in area (1)
Remove the luggage compartment floor.
Fig 1: Identifying Spot-Welded Adhesive Joints Area