I had my F900BT installed professionally but the adapters they had in stock were the Metra XSVI-9003 and they didnt work in my car. I read later on that the were issues with getting it to work with some 2007+ VW vehicules. So what the installer did for the meanwhile until I can find an adapter that works is install a manual kill switch to turn on and off the headunit. Its a little annoying, but its only temporary.
This is what he tried:
http://enfigcarstereo.com/shopsite_sc/s ... _9003.html
From what I understand, this is what I need?:
http://enfigcarstereo.com/shopsite_sc/s ... 2