That sucks sorry, let me know how you make out when you reinstall it? did you take the whole mirror off? It probably wouldnt have hurt to make the the mirrors a little bit thicker across the board but that would have to been done with CAD and the 3d'd prototype then sent to be manufactured. cost would have been way to much. but if it doesn't work out for you we'll get it sorted
yeah 100% isnt forgiving as plastic that's for sure. I wouldn't have tried it myself to be honest. I am the king of over torquing, forcing, and not reading instructions. Best for me to leave that to the guys that do that kinda stuff.