Just a thought. I have seen a lot of videos and pictures (not just of the prius) of people having fun with the back-up cam. Obviously we can conclude the car in in reverse when this is happening... Anyone have any good stories of this? It has to have happened more than once.
That's not necessarily as obvious as you would expect... When I first got the car, I went in and added a little button to my dash. When I push it, the backup camera turns on, regardless of the gear I'm in! I've had friends riding with me play with it while we're driving down the highway, or parked in a parking lot.
