[tlorenz2014]

My car does not have surround view or rear view camera

I plan on retrofitting a rear camera, however, the control unit for surround view is similarly priced to rear camera control unit

I’m thinking of buying the surround view control unit instead of rear view only control unit so I can upgrade in the future

Will surround view control unit work normally with only rear camera plugged in and show me the rear view, or does it need all cameras plugged in for it to work?

[Billfitz]

I'd forget about the camera retro-fit and get a rear view mirror camera. I installed one of these: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It gives me a rear view that's wider than I can see through my side view mirrors. It has a front view camera as well, so it doubles as a dash cam. Since I have a rear camera for parking I installed the mirror camera on the headliner just inside the rear glass, for the best side view. For a better result as a parking camera install the camera on the outside above the license plate.