Does video from the backup camera or side mirror camera travel to the (NAV) display via the CAN bus or some other mechanism?
I'm really curious if you can get access in some way to that video - or replace it. (E.g., grab it from the bus and put it on your own display with your own overlays. Or replace it with a stream from a different camera.)
Update: I should have made this clear originally: I'm speaking of video from manufacturer standard equipment (the backup camera and side mirror camera are standard features of the car).