I just got my Gateway 500 a few days ago and planning on having it installed this weekend. I wrote Dension a while back asking do I get audio with my setup, which is G500>TV Tuner>COMAND 2.0 and this is what they wrote back just yesterday:
Hi the video out is a simple RCA out, forwarded from iPod dock side, so it can attached to your TV module, but i'm not sure if you choose TV on headunit, the headunit let's for you to listen for cd-changers sound, where Gateway provides it, if not then may you have to connect a simple 3.5" to RCA cable from the headphone out of the iPod to attach it's sound into the AV in of the TV tuner, and this way may you will be able to use it. The gateway forwards the video signal.it has got the yellow RCA out for video playback on external display.You can watch on an external display only played video from iPod, but in this case you have to change from Dension UI, to iPod UI, so iPod buttons will be released, (general control like >| |< and >> << can be controlled from headunit too) select your video file on iPod, select TV out, and it will be displayed on the external display.Thank you for your patience.If you have got any further questions, please contact us again..Best regards Dension Technical Support Europe
http://www.dension.comhttp://support.dension.com
So, it seems they're not sure if the G500 audio will works on default with video out, but at least it sounded like I an hook up the RCA audio cable from ipod to TV-tuner to make it work
Will post pictures after the installation this weekend