Well I decided today I was going to find a way to put that mirror on regardless of whether I had the correct parts or not.
I'm not above fabricating something that will work if it gets the job done.
Be careful when removing the door trim panel. There are two bolts behind the courtesy light that help keep that panel on.
Remove the courtesy light, then get the 10mm bolts behind it before trying to take the rest of the door panel off. Then there is the 10mm bolt in the top of the inside door handle.
A tire iron is useful for prying loose the push-in barbed retainers on the back of the door panel. Just be careful and patient and you'll do fine.
Unplug all of the switches once you get it loose.
You'll need to leave the window up, and then you'll be able to reach up to the mirror studs. You'll have to do all of this by feel.
Instead of waiting for Pontiac to figure out what parts I needed on the inside of the door, I just used a pair of spare 10mm bolts and some old washers I had laying around.on the back side of the mirror.
The rearmost one was hard to tighten due to a lack of room to work with, and I didn't tighten it much more than finger-tight. A long-handled combination 10mm wrench did the job well enough. I was able to use a 1/4" drive ratchet on the frontmost nut, and got it on a little tighter.
Total time for this job was <45 minutes start to finish.
Difficulty level was a one on a scale of 1-5.
Good luck with yours.
The really tough part? Trying to put parts on it as fast as she can knock 'em off!