Aux Input For Bluetooth A2dp / Avrcp For Audio/phone

[Tazer]

I fed up with using wires to connect my iPod to the car! So I want to connect a Bluetooth stereo A2DP / AVRCP audio device (like a Motorola T605) to my Mark Levinson audio system in a 400h them I won't even have to take the phone out of my pocket to play music! Plus I will be able to connect more than one phone automatically and I won't have to put up with the cr*ppy sound on the Lexus Bluetooth phone connection anymore...

The problem is that I can't find any leads / wiring diagrams that will allow me to connect directly to the head unit input (like the Aux In on every other manufacturuers car - I mean who uses tapes these days?) so the volume, bass, trebble balance controls etc work for the iPod as well. The SOT / ISO leads I've found seem to allow connection directly to the speakers so that's no good.

Does anyone know how to do this? Does anyone have a wiring diagram? I'm an electronics engineer so I may be able to work up an interface if I get the right info - then I can post it on here...

I had a good look around the forum but I could not see any posts on the subject - if I missed it, sorry, could you direct me there?

Thanks!