I have the same mount with a life case for my iPhone.
I had a rear aux jack installed on my stock radio, bought a cable with an aux plug and USB connector at one end and an iPhone connector on the other.
Took off the outer fairing, plugged the aux into the back of the radio, pulled 12v from the cig lighter and tapped in a USB port, plugged the cables USB in there. Ran the cable out of the fairing and up to the front of the gas tank.
Plug it into my iPhone and it charges the phone and plays the phone audio through the stock speakers.
I can listen to music and when the GPS has a instruction for me it turns down the music, gives the command and then goes back to the music, I don't have to touch anything.