What is this plug on the rear lift gate?

[sfc_jones]

why would the op want to mount another camera when there is one already one mounted? Just curious

 

[Big Mama]

If you're like the rest of us you'll find all kinds of buttons and plugs that do things you never new of. The question for you though is why are you looking to replace your factory camera? As for the degrading rubber piece you can find a rubber grommet or plug at the hardware store but they do sell just the rubber housing if you want a factory piece. I replaced mine for the same reason. It's a pop out pop in repair.

 

[ritzz]

My rubber piece wore out, so I put blue painter's tape over it then some black electrical tape over it. Has yet to fall off/out.