Was always curious as to why Chrysler placed rear view mirrors on the dash of certain 50's cars? Seemed too low to be of much help as compared to ones mounted to the front of headliner.
If you can see out the back window, why does it matter? If it is up high, and you can't see shit you have put it some place else. Ya gotta consider the size and shape of the rear window, too.
Basically a 'styling' statement, worked OK as long as no one was seated in the center then it could be an issue. As you noticed, it didn't stick around very long....
I know on my old IH truck that because of a change in bed (IH to Chevy) and the rake of the vehicle that with the mirror mounted on top near the headliner that I had a great view of the tailgate. One day the mirror fell off and landed on top of the dash, only then did I realized that I could see more with the mirror in its final resting place.
When I was a young 'un I thought that the dash mounted mirror in my friends moms station wagon was cool. Then we figured out that it was really easy for his mom to use it to spy on what was going on in the back seat.