I was thinking along the lines of a substitute or overlap for the Garmin Varia RVR315 Rear Radar function, sort of an electronic rear view mirror as well.
Anyone played with some of the $30 alibaba dashcams?
Seeingn it might be a low cost "test of concept" before getting a $$ GoPro or other $$ fancier set up with wifi to bar mount cellphone I use as a GPS