oh, almost forgot about the Bt dongle...

it is an iLive unit, it does music streaming in stereo from BT source and sends that music to a 3.5mm output, that can be fed into your choice of input. i bought mine for about US$18, including shipping, online, turned out, my local Wal-Mart has the same unit for $25.

I use an HTC One X+ android phone. for navigation i use Waze, for music i use either pandora or Tune-In app that pull live feed from radiostations worldwide... I also have 12th generation OE BMW ULF unit for the telephone operation. in the telephone itself i have chosen to use the iLive device (once it was paired to the phone) as a "multimedia interface" and the "BMW ULF" as a "phone interface".

as a result, when I put my HTC into a cradle, the cradle activates a "car profile" that has Tune-In application launching and i tune it to my station of choice. it is also set up so that the phone BT activates and connects to the BMW ULF (which is always active with ignition start) and simultaneously connects to the iLive device. the phone starts streaming the radio broadcast. for me to hear the stream, i need to press "MODE" button on the monitor, to select the AUX input, and i have my music coming through my speakers, with DSP, treble, bass, speed sensitive volume all functional...
at that moment, if i desire to activate the Waze, I can do so, while the music continues to stream... the voice guidance from Waze mutes the music stream to inform me of turns or traffic conditions, and the music comes back...

if, during that process i receive a phone call, the streaming pauses, and mutes on the speakers, while the active call comes through the speakers, as the BMW ULF takes over... once the call is finished, the Tune-In resumes the play - it buffers, and then picks up the broadcast... while the call is active and the music is paused, the voice guidance from Waze comes from the phones speakers (and it sounds funny, like a little kid trying to get your attention...)...

if I decide to use Voice commands of my BMW ULF, I press talking head on the steering wheel, the streaming mutes (and then pauses on the phone), the BMW ULF lady is listening for my directions, say i want to call somebody, places a call - everything as i described earlier...

the same applies to Pandora and Google maps, even though i prefer Waze and Tune-In...

this type of BT operation is heavily dependent on the telephone, if the telephone can allow separate operation of music stream and phone operation, and if the phone allows music stream and overlay of nav guidance...

I hope my explanation makes sense... otherwise - ask questions...