I think its Volkswagen that has a retractable camera that hides behind a panel, so its only exposed when its actively being used.
I could picture problems with that too though. For one, it would freeze shut in icy conditions. Depending on how delicate the mechanism is, I could imagine it getting gummed up with dirt & dust, etc.
I don't really have a problem with my camera. Sometimes, the picture is a little obscured, but I can still usually see enough for what I need. I wipe it off when I'm standing back there and I think of it.
2016 Chevy Colorado LT V6