So I bought my first set of the CMM mirrors a couple of years ago. As I mentioned previously in this thread they are convex and can throw off your perspective when needing them for something like backing up, so I had the original set reflector replaced with a flat reflector.
The catch with that is that the mirrors then have a severely restricted field of view, but worked great for something like backing up. So in thinking how to improve this, I finally just thought I would by a second set and here is the result. The bottom mirror is the flat reflector, that would of course then make the top the convex mirror.
I only did a brief test with this setup today, but my first impression is that it should work.