2.1 Steel Surface

WARNING: This page is about a different car, the 2010 BMW 550i, 2009 BMW 550i, and 2008 BMW 550i. However, it is still accessible from the selected car via links, so may be relevant.

Grind bonding surface with a metallic bright finish for better adhesion.
Clean bonding surfaces with cleaning agent R1.
Allow cleaned surfaces to dry for approx. 5 minutes.
Bonding surfaces must be completely dry.