When I setup my camera (rear and right side) I made to so the rear camera is on all the time with the side manually selected. With my rear view camera I am able to see if any vehicles that are beside my toad and can easily/quickly determine if my toad will not impact other vehicles while changing lanes. I have found it difficult to judge when using the side view camera if it is ok to change lanes. In the side view camera I am unable to see my toad so it ended up as a educated guess.
1999 Bounder 32H Ford V10, 2012 Ford Focus, Pretty DW, 2 cats. Retired USAF