(I am hoping this isn't too off topic...)
I am helping a friend this weekend install a 9w7. He has a dealer bluetooth in the car already, but doesn't know which type it is. He suspects it is Nokia. I have helped him change the RNS previously and we didn't sight the module (but didn't look too hard either).

Can anyone suggest what might have to be done to successfully remove the old bluetooth? I don't know how something like a Nokia would integrate, but my guess is:
- power & ground
- audio mute
- audio from BT into inputs on radio

Firstly we will look deeper down the back behind the radio to see if the module is there. If not, around glovebox.... but don't know where else to look.

In terms of wiring, should we be expecting a few parasitic connections on leads onto the back of the unit or what? Can anyone else provide some suggestions of what to look for?