WARNING: This page is about a different car, the 2013 BMW Z4, 2012 BMW Z4, 2011 BMW Z4, 2010 BMW Z4, and 2009 BMW Z4. However, it is still accessible from the selected car via links, so may be relevant.
TIGHTENING TORQUE SPECIFICATION - REINFORCEMENT, BODY
Type
Thread
Tightening specification
Measure
1AZ
Upper section, support, to support carrier, wheel arch