In post #11 in this thread - https://dashcamtalk.com/forum/threa...-sg9665xx-a118xx-and-b40xx.11698/#post-152630 - I have a picture of how dark the tint is in my car. In post #15 there's a video clip (2nd last) of the SG9665GC captured through that glass at night.
This may give you some idea of which way to go as the '12RC' uses the same sensor but a different processor. I don't know if this is a valid comparison or not - possibly @jokiin or @Pier28 can elaborate.