I am in a wheelchair and carry it on the back of the car when going most places. I need a way to turn on the backup camera while in DRIVE so I can check on my char as I am driving. I have to have others put the chair on the car and "trust" others to do it correctly. I would like to add a pushbutton switch on my console to quickly check on my chair. without turning on the reverse lights. Any suggestions or wiring diagrams I can follow?

 

Apparently you can go into a service menu to see the backup camera feed while driving, see instructions in this video:
I haven’t tried it myself but it seems straight forward.