For those of us that already have the navi-tv-dvd mod, I wanted to know if anyone out there who has installed a back up camera, had figured out how to have the navi-screen automatically switch to the camera view when in reverse; as in without the need to flip the switch that alternates between the normal screen and the one for the dvd/tv screen. I would hate to always have to switch the view on the navi, just to see the back up cam; this would be most inconvenient.
I guess you would have to have done this mod to know what I am talking about.

 

there is a black up light trigger that you hookup to your reverse lights and when your reverse lights get 12v it automatically switches over...

 

Brandon is correct.
Depending on your interface with the Navi, it should have a specific wire that ties into the reverse lights. Anytime your reverse lights are activated it automatically overrides whatever video source playing on the nav screen to your camera.
I have an "On - Off - On" switch as well on my dash to the right of the VSA/mirror controls. One position "does" allow me to select rear-view mode at all times, the other position is for DVD's etc.. The "off" position gives you the factory display. As mentioned though, it still doesn't matter what position the/my switch is in - if I shift into reverse, the camera overrides..

Cheers