Anyone know if its possible to wire up the reverse camera to a switch? Maybe to a button next to the vsa button.

 

sure. there is a wire from the tranny that runs to the nav unit in the back. it is a blue wire and when 12v are applied it turns the camera on. if you splice this wire to add 12v you can make it happen. If you check some of my older posts there is a wiring diagram that shows the wire.