Rear-view car cam: Anyone have the kind that slips over the rear view mirror?

[Filliam H. Muffman]

Dedicated ones for automotive use that use WiFi for video are a little easier to set up because they (hopefully) only need a 12 V power lead. You then need to decide between always on 12 V, or trigger it with the backup light lead. I think most of them can focus further than 14"-16". License plate mounting might cause you an issue if your plate is really close to the trailer ball.