This is how C3 looks mounted in my car as a rear camera ( Dashcam ).
I did some quick DIY in order to slide in under ceiling upholstery.
Video cable is routed also quickly. For more professional install all cables can be fully hidden. For test purpose I routed cable as shown in pictures.
If windows are not tinted, then Rear C3 can be seen from the outside for Van ( mini-bus ), SUV, etc. vehicles drivers which are higher than standard sedan car. ( pics below )
If driver behind you have standard sedan car, then from his sight of view ( vision ) C3 blends in with rearview mirror and is hard to see it. ( pics below )
Instead of tinted glass I bought
UV CAR SHADES
UV Car Shades allow to drive with open windows in summer, but at same time protects from direct wind and sun
UV Car Shades allow to install rear dashcam the way that camera will be behind ( or on top ) shades, - this way can record clearly.
Below you see my quick install. Not 100% perfect, still little gap can be seen on the top where C3 mounted. I just need to do some DIY for rear UC Shades mountfixing and also to move C3 sligthly more to the glass ( also maybe to do new DIY low profile bracket ), so shades will cover full rear windows. Without camera those shades cover rear window 100% perfectly due to being custom fit.