Has anyone used the bluetooth handsfree abilities of this nav? I was going to get a cheaper unit, till I noticed this feature. My last car has a bluetooth handsfree system built in, and although you are totally cut off from your address book, it does make calling home and your woman a whole lot easier. Plus its hard to shift gears and hold a cell phone at the same time. I'm wondering how well it works. Plus do you know where on the unit the microphone is located. I ask that odd question because I plan on trying to mount the unit in my dash in a way where, if the mic is on the back, it probably won't hear me very well.