I want to connect my F500 directly to my car-radio. The aim is to use all functionality of my radio for playing music ( Aux In) and mute that input when navigating (Nav +/-) and to give the navigation only to the front speakers...

 

My idea is a cabling as followed

 

Navi ---> Radio

Audio out ---> Line in

Audio out ---> Navi in

Amp out ---> Radio mute

 

The problem is, that Amp-Out gives a signal when the F500 gives any kind of an audio output, independent of the source (music or navi)

 

I need a possibility that only in case of navigation output a signal on Amp-out is raised and if I play music the signal is not raised.

 

Any ideas, how to solve that issue???