hi
ths forum thread should help
RangeRovers.net :: View topic - Fitting Hands Freee Microphone Obviously you can ignore the cradle in that photo as you want bluetooth.
it shows the system im talking about and is what i copied when installing mine. The wiring loom/mute lead is quite literally just that, it connects to the back of the radio and has the existing radio connectors plugged into it. its pricey but there was no way i was having some flashy all singing all dancing multi colour, million band, sat nav chav radio installed in my P38. the black box is because of the Harmon Kardon sound system. It takes the sound input FROM the car kit you have installed and shuts the radio up (with the radio displaying TEL) and then plays the sound through the door speakers, its basically because the HK sound system has amps in the doors rather than the radio and this box just allows the special wiring loom to interface with the system.
the Nokia CK-7W is the car kit itself, you plug in the audio line from the wiring loom into it and it provides the conversation you are having out through the new wiring loom and into the speakers.
I mounted the microphone for my car kit just above the rear view mirror
on that black bit that holds it to the screen and that works really well, everyone car hear me ok. you run the mic line from there, alone the headlining at the top of the screen, down the a-post and back behind the dash.
the car kit also comes with a button to allow you to pres to answer and to press to hang up and adjust the volume and i mounted this right down by the gear shifter just infront of the heated seat button, again, easy reach and pretty much hidden from direct line of sight.
the brains of the CK-7W, the little black box that can connect via bluetooth OR a cradle just goes behind the glovebox, inside the dashboard as shown in the pics on the thread link i posted.
HTH, let us know if you need anymore help
-Wills