Can't help you on the glue but can anyone can recommend a method to removing one of those mounts?
Hope you don't ming the piggyback post Jeff.
Stop by a glass shop for both your issues. I bet they do them both without charge too.
I used a small amount of 2 part epoxy (be sure to sand the suface of the metal base to get the best adhesion) and also mount the mirror as high as possible (to gain the most forward visibility) & still be able to remove it from the base. Also when off roading, I keep a screw driver near by to remove it all together, you'd be surprised how much of your forward view is obscured by the thing.
How high did you mount the base? That sounds like a good idea.
This is going in a ST but I dont think anything interferes...
.
The mirror fell off the old Disco a year ago. The magic super-glue-ish stuff didn't work. I stopped in at the local windshield shop...the guy said he wouldn't touch it.
The two part epoxy they normally use gets too hot and had cracked Disco/Rangie windscreens in the past.
Watch where the sun visors fold down. If the mirror is mounted too high the sun visors will hit the mirror. At least on the NAS D90. Not sure what vehicle you have.