I bought my car, a 2000 Buick Regal, in January 2005. In February 2005, I pulled into my parking shelter with a little too much gusto and smacked the passenger side mirror on one of the posts, breaking the mirror assembly in the process. It just now kind of sits in there, wobbling, and I can?t get it to stay in any one place. It hasn?t been a big deal to me, because I rarely use that mirror and look over my shoulder instead. But I know I should get it fixed, because hey, can?t have too many mirrors, right? My dad noticed the mirror was broken last time he came to visit and told me I needed to get it fixed. Suffice it to say that I?d rather spend 200 bucks on anything other than a mirror. Well, he?s coming to visit tomorrow (I only see him once or twice a year) and we?ll be taking my car around my city. So I know the subject will come up again and make the visit awkward. I?ve tried wedging paper in there, and it holds for a bit, but then the paper just falls inside the assembly and it doesn?t work anymore. I am reluctant to use duct tape. Any ideas for cheap, clever fixes? This is last minute, but I?d appreciate any ideas! Thanks much!
P.S. – I know I should get it fixed; I will, I just need a quick fix for this weekend.
My brother did the same thing the first time he pulled out of our driveway. Well almost, he whacked the mirror off on another car in the drive.
You have to look how the mirror is attached. Look on the inside of the door, do you see a little triangular body panel? If you do take it off and there should be 4 bolts holding the mirror in place. Unbolt them, my guess is that were the bolts go into the mirror broke, it is usually just threaded plastic. If you haven’t lost all of the bits of plactic I would use JB Weld or a similar product to glue them together, making sure you don’t get glue into the threads. Let it dry and bolt the mirror back on, but apply very little torque or you will break the glued seams.
Give it a try. If it doesn’t work you can always look for a salvaged part from a scrap yard.
Take the part off and tell your Dad you have a salvage yard looking for the part.
You don’t need to spend $200 - you can find one from a salvage yard (check the yellow pages for used auto parts) or use eBay. eBay will also probably have plenty of new aftermarket parts for cheap. As jsutter pointed out, depending on the damage and such you may be able to stick yours back together, though I think you’d find them available cheaply enough that it might not be worth the trouble. Start by finding out how to remove it. If there isn’t a trim panel opposite it on the interior of the door you might have to pull the interior door panel. This is a bit of a PITA, but not as bad as you might think. They’ve become more and more rare, but if you can find a “pull your own parts” salvage yard that has the right mirror, you can do your learning and practice on the junker at the yard.
Sort of like one poster advised, 5 minute epoxy (the kind where both hardener and epoxy sqeeze out at the same time in this case possibly would be easier) works wonders in all kinds of situations. 
If possible, ruff up, then clean dust off of any 2 surfaces you are epoxying together with sand paper first to ensure a good bond.
It’s not the outer casing of the mirror, it’s just the mirror itself that’s moving around. Whatever holds it in place inside the “shell” (I guess?) is what has been shattered. (Sorry if I wasn’t clear… I am not good with car terminology. Assembly might have been the wrong word.) I will look into epoxy and see what wonders I can work with it. Thanks so much for all the replies!
Given that this is the case, you could look to see if there is some way to take the assy apart. This is unlikely, but you could try to pry the actual mirror off to give you access to the interior. Then break out the epoxy. If you try this and break the mirror, this is no big deal - find anything of approx the right size & shape (auto parts stores) and glue a new mirror in.
But I’d be surprised of you can get a direct fit replacement of the whole assy for $50 or less.
Get some “Great Stuff” foam insulation in the aerosol can. It’s at the hardware store. Spray a small amount at a time behind the mirror until you’ve almost filled in the cavity behind the mirror. Be extra careful not to touch the wet foam. Try to aim the mirror before the foam starts to harden.
That is clever.
I will mention that the actual great stuff super-expands and may be hard to control in terms of final volume if you don’t have a lot of experience with it. You very well might end up with something very comical out of that attempt.
So I will mention that there are other expanding foams that are minimally expansive and may be easier to work with for something like this. If you decide to try this, check out the different kinds, read the labels & make your best guess.
A regular serrated knife cuts the foam off well, and a razor blade should clean the mirror, you could even color the foam black with a sharpie. I see a happy moment until your father in law tries to adjust the mirror. If it is an electronically controlled mirror you will have a mess to clean up unless you have to replace everything anyway. Please post on Monday how the weekend went, We are dying to know!