WARNING: This page is about a different car, the 2011 BMW 750xi, 2011 BMW 750Lxi, 2010 BMW 750xi, and 2010 BMW 750Lxi. However, it is still accessible from the selected car via links, so may be relevant.
Bend wire end approx. 10 mm and insert in notched tip.
Pierce wire starter with uniform pressure through adhesive bead, wire end (bent part) must be positioned on window glass.