My top tabs were gone a long time ago, and a PO had "repaired" it by stuffing some foam between the mirror and the bracket, leaving ONLY the bottom screw holding it all in, so it was applying a bending moment at that bottom screwhole. I saw this crappy fix when I had to replace the swinging pivot with a long bolt & washers last year and decided to leave it be for the time being.
As expected, that plastic eventually failed a few months ago, and my mirror fell out, so I taped it back in as a temporary measure.
After reading all the JB Weld failure stories in this thread, I abandoned my original tab-reconstruction plan and did this zip tie fix. So easy! Just like in the pics, I slid one of the zip ties through the gap between the central pivot and a little tab on the inboard side (toward the cabin) on the mirror housing, and looped it around the entire mount (not just the top part, since I needed the top AND bottom to be secured since my bottom screwhole was toast). This single loop seems to be enough to hold the mirror housing into the relief in the mount after cinching it down nice and tight. Took a trip around the block and saw no shakiness or anything over the bumpy areas.
My power adjustments still work great too.
I'm super stoked -- just in time to get my safety inspection done tomorrow!
Thanks floridan surfer for this great fix!