I just added a switch to allow me to turn on the rear view camera. To do this, you fake the sensor into thinking the back door is open by grounding a white/blue wire at the rear passenger corner of the van. This was explained in another thread... sorry I forget who to credit for the initial research.
While driving, you hit the switch which grounds the wire. Of course that sends an ongoing "door open" signal to the computer so the rear lights go on and the "rear door open" message (and beeper) shows on the dash. In addition, on mine, every time you stop at a light, the "read door open" message and beeper happens again!
Following that logic, if you were to cut the white/blue wire with a switch to break the wire, it would not send a door open signal to the computer. Turning the switch back on would restore the door open reminder function. Note, when the switch is OFF, the rear camera would not trigger when shifted into reverse!
I remember when cars were wired without computers... life was simple. Now we can't do much to modify things because the software decides what makes what happen..... KISS was better! (insert picture of grumbling old guy here)