I decided to try a DIY microphone install in my X5 e53 06.

I did it , I got the headliner panel out. There were four torx screws total, two under the light assembly and two under the area where there might be a sunglass holder if I had one. Whatever I have instead needed to be pried out to get to the other two screws. I was able to find the microphone wire/plug, it was taped down to the main cable of wires that run across head liner on the drivers side. I was able to squeeze my hand in there and unravel the tape to free the microphone plug. Then I just had to fish it over to the right side of the button panel where the microphone will live. Now i am ready to order the microphone and plug it in. I can't believe I did it. One small step closer to BT....

BTW, I tried to switch the sun roof switch over to the microphone opening but it does not fit nicely, the opening would need to be filed down or something.