I've been looking for a vox circuit switch could detect the audio and use the signal to mute the head unit with a relay and pipe it through the phone kit.
This is the circuit I want to try and make
http://www.aaroncake.net/circuits/vidswitch.htm but I don't know where to get the parts from, the online catalogs are kind of confusing. Any help would be welcome!
I started a thread here on PPBB too, no replies yet though.
Chris.