The good news is BT dongles with a headphone jack exist. I'm not sure how pairing works, and I suspect that three devices is one too many. Unless you can route the 9500 through the Nav V, which I doubt. Ditto for the iPhone (calls probably handled but no joy with getting music). About the only hope is to route the Nav V and 9500 through an audio mixer (Google and eBay same) with a second BT dongle which would is paired with the helmet BT dongle. Plan on carrying a lot of batteries. Plan on being frustrated and angry. A lot. Google on "Bluetooth adapter jack" and ditto on eBay.
BTW Nav V on a Feejer and not a Beemer?