I was actually able to get my factory NAV in my 04 Limited to play DVDs. There is a company out there that sells a nice little interface which goes between the Navigation DVD player in the rear of the truck and the front Nav unit. All this interface really does is interupt the video signal of the DVD map. So in essence the Nav is still working the whole time..you still get voice prompts and everything. There are only two catches. One you need to buy yourself a Car DVD player to play your DVDs, and second you need an interface to allow the sound to be played through your factory system. I ended up going with VAIS Technologies for the sound interface b/c the interface also allows me to use my factory nave to control my ipod.