There's a module called navtool. It's a basically an aux input box where you're borrowing your nav screen to use it as other sources. It doesn't affect your music or cars navi whatsoever and able to view it while you drive.

There's another way to do it without the navtool but will require you to cut and ground the Parking brake wire and add a inline switch for the VSS (vehicle speed sensor)wire.

I would look into the module instead of hacking up the wires IMO.

in other words like your not supposed to be able to watch a movie when the car is in motion

i was told the screen turns off when your driving like the double dins. weve gotten around that on the radios but can you do it on that system?