I had a droid razr and now i have a Galaxy S4. On my droid i could have my bluetooth connected and then plug in my audio that goes to my car stereo. When i got a call it went to the bluetooth and the music stopped. If i turned off the bluetooth then the audio was transferred to the stereo if i unplugged the stereo the audio went to the bluetooth. Basically it knew where to send what based on what is connected. It didn't work that way this morning with my new S4. i had the bluetooth connected and then plugged in the audio. I was listening to the radio when i got a call the call came over the stereo and not to my bluetooth. How to i change this if i can.