I have a lovely Audi A4, such a nice lass. Anyway I took out the radio to have a look see as folks have pointed out that i has pre-amp outs, and indeed it does. it ALSO has Navi audio in, along with telephone and such as well.

It has 4 connections for Navi
Nav +
Nav -
Nav Con
Mute

And I looked int he manual and low and behold I can set the nav volume through the HU, how nice. My guess is I'd have to use 2 sound cards, one for normal audio one one for Nav

So my question is, what is Nav Con? Does a voltage need to be applied for nav input to work, I've read on Audi forums that Nav voices should play over the music. I have interest in muting on Nav voice. Ok, thanks!