Car audio Bluetooth Help

[Jeremy Jones1981]

ok heres my problem and i hope someone has figured out away around this when im in my car i plug my gs3 up to the radio and listen to music and i also have my bluetooth in my ear now when i recive a phone call the sound from the phone call comes through my car speakers and not my bluetooth untill i unplug the cable from my phone is there any way around this so that i dont have to unplug the cable when i get a phone call???