My friend did this for me on my e92 a few weeks back. Works flawlessly!
Regarding the sunroof issue:
Make sure you ground it to the a good bolt. When we had the voltage meter the power read ~14volts, whenever the sunroof was used it dropped down to 7-8 or even lower, which effected the v1 turning it on and off.
- Make sure the ground is secure, I think we used the larger bolt that was close to the left side, further in.
- Check the voltage on a bunch of the wires, we tapped into 1 of the larger ones and it worked fine.
e92 / Sparkling Metallic Graphite - Coral Red / Sports Package / Ipod Adapter / Steptronic