I promised something by today so here goes.
I haven’t found the proper mirror but the concept is sound.
I will attach a small convex mirror to a metal plate that will have a protective cover so that the metal won’t scratch the glass. The metal will be held against the glass with a rare earth magnet on the inside surface of the glass. The magnet won’t move around on the glass because it will be held in place by double sided tape. Voila!
Placed on the lower left corner of the right window (next to the passenger seat) this is the simplest solution. Prototype is to crude to include a picture. But you get the idea.