WARNING: This page is about a different car, the 2016 BMW Z4, 2015 BMW Z4, and 2014 BMW Z4. However, it is still accessible from the selected car via links, so may be relevant.
TIGHTENING TORQUE SPECIFICATIONS - REINFORCEMENT AND BODY
Type
Thread
Tightening specification
Measure
1AZ Upper section, support, to support carrier, wheel arch