Phone Problems

[EBCBbaLL]

I didnt know exactly where to post this but i have a hands free device set up in the X5 and i think a fuse blew. It was originally my dads company car so someone his company hired installed it. Its got the phone holder comming out of the dash left of the navigation, the microphone by the rear view, and the speaker on the left of the passenger seat. All the wires go back behind the dash so i cant see anything. But what im trying to figure out is where he tied the power into, any ideas? I tried checking fuses in the back and the glove compartment but theres quite a lot to check every one. And also, if i took it in the dealership could they find the problem and fix it... cheaply.
Thanks
-Matt