ok, to watch dvd's without the ebrake on, ground the red wire under the console to the bolt that holds the console to the floor.

Theres a green wire running over to the fuse block behind the dash just left of the steering wheel. Cut this wire.

Behind the navigation, look for a plug in the back of the nav with a yellow, green, a couple white, a couple black, purple, and a few other wires (from memory, theres probably about 8n wires in this plug). Cut the purple wire and extend the wires over to one of the empty switch locations. I used a rocker switch from a scion led interior kit. Install the switch in the dash.
Now you can flip the switch off to watch dvd's or to type the nav keyboard.
The nav map will not track your movement when the switch is off, so after you are done typing, flip the switch back on and it will resume navigating.