I've popped my mirrors out of those ridiculous pop-on mounts for the last time.

I'm seconding the recommendations people have made on behalf of the Magic Mirror Mounts. Took about 20 minutes to install (mainly because my workbench is a mess), and the mirrors are held in place by amazingly powerful magnets.

If you find yourself having to remove your mirrors regularly to work on the bike, these will make that task MUCH easier to perform. I've always feared that I was going to break something removing the mirrors, but these remove that fear.