Tip 1:  Speed up the electric roof (transtop)
You know, when  the trunk is closing there are two stops.
When you double-click on the first stop, the trunk will be closed without a secound stop.
Tip 2: Reset the ECU (engl.)
Zurücksetzen (Resetten) des Motorsteuergerätes (german)
Tip 3: Selbstdiagnose und Fehlercodes des Motorsteuergerätes (german)
Tip 4:  If you interested in the AUX/FOG-Light switch that's located behind the hand-brake, then click here ...

 
External links: "do it yourself" How 2