I am thouroughly confused on the information concerning the grey/black mute wire that I find connected to my factory HU. I believe it was the B6 wire. . . I have a 2006 with Bose, Onstar and XM. Is the mute from onstar through their serial data, or can a Bluetooth kit be used connected to this to place the HU in "phone" mode. I have done the install and it does not seem to move over to the phone mode allowing me to hear the called party. I can use the onstar phone button to hear the called party for a brief time until the onstar times out. I do, however have to compete with both voice activated dialing women talking at the same time. I know that some of you guys have done this install, and I was hoping to do the install without the relay method that turns the HU off.