The Nav system doesn't have bluetooth. The phone button is nothing more than a mute button. I have the Parrot bluetooth unit that works with the Nav and all that happens is the radio mutes itself and says "phone" on the screen and the audio is routed through the speakers. There is no onscreen display. There is nothing built into the nav unit itself. All the functionality is a part of the bluetooth kit. Don't think for a second that the factory nav radio is bluetooth capable.
Here's the Parrot unit mounted to the car...
Here's what the NAV "phone screen" looks like....
-Tim
2006 Mercury Mariner Hybrid AWD
Black with Pebble interior
Premium Package with Nav & Moonroof
Current ODO:
22,530
Typical Drive: 20 min crosstown in heavy traffic (3.5mi there and back twice a day)
Last three tanks:
26.09mpg
Best Tank:
31.7 mpg calc. (35.0 mpg Nav)
Best Trip:
37.1 mpg for 153.8 miles
457 Gallons of gas saved
That's 9,150 lbs less CO2