The dealer seems to think it works through the NAV. But that is not possible with just a GPS sattelite.

Any ideas if one can tie into this hidden phone and make or receive calls?

 

Yes, there is a phone - it's in the trunk. You can tell it's there becuase the signal strength is shown on the i-drive screen.

On North American cars anyway, no one has figured out how to use it to send calls (to my knowledge) - I have tried dialing manually but no matter what number is dialed, it always rings BMW assist.

Some people have answered wrong numbers using this phone and have asked the caller what number was dialed - they have then been able to use this number to recieve calls in their cars.

Also, for some vehicles, the phone number is shown on the bluetooth pairing card - not mine though.