I'm installing a Bluetooth handsfree cellphone kit in my car. It was designed to play audio thru the audio system's speakers by connecting between the headunit and the speakers (it assumes the headunit powers the speakers directly).

Fortunately this kit does have a standard stereo mute lead. How easy would it be to modify the Empeg's software so that instead of pausing or muting the audio, it switches to Aux in where I will have the handsfree car kit connected to?