Factory BT mic with aftermarket stereo?

[CoreyMac]

I'm looking at putting an aftermarket system into my new 2010 GT, the AVIC Z110BT is probably the frontrunner. I'm not even sure where the BT mic is in the factory setup but I'd prefer to use it if possible. Can the AVIC use the factory mic or does it have to use the one you get with the system? Would there be any disadvantages to doing it this way?

 

[beldecca]

I'd love to hear the answer on this also.