Adjusting pretension
WARNING: This page is about a different car, the 2010 BMW M3, 2009 BMW M3, and 2008 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
Remove rear window cavity cover strip .
Turn adjusting screw (1) with special tool 51 2 220 until correct pretension is reached.
NOTE:
With hardtop closed, side window glass (2) must run correctly into hardtop seals (check only when window cavity cover strip fitted).