I bet after numerous replies you will end up with something similar to.........
1. High mount has numerous advantages. After all, a camera serves as a vantage point, and the higher vantage point is simply superior in almost every way.
2. Drilling holes in our RV's give us pause. And it should! It's something that must be done properly. But it isn't brain surgery. It's just a point of entry, and absolutely necessary if you desire an awesome camera result.
I assure you there is tons of experience and advice here for accomplishing this with excellent results. Take your time planning. Gather everything you need to carry that plan out. And whala, you'll be posting pics of your rear view camera for the rest of us to want one too.