Floppy Mirror
 

What's supposed to keep the mirror (the whole assembly not just the glass) from flopping around on the mount(the part that bolts on to the door)? The PO had a piece of a wood screw or something through a small hole on the side of the mirror that sort of kept things in place, but it never quite sat right and it didn't do a good job keeping the mirror in place on the highway.

I looked in the parts diagrams and I don't see any parts that I'm missing. It looks like the mirror assembly just sits on top of the mount. Is my mirror/mount just worn out?

Well, there is a big hollow screw with a spring on it that screws through the mount to the mirror. The spring holds things in place nice and tight. There is also a nylon, 3-sided piece that fits between the 2 pieces that helps to keep things weather tight.

Sounds like your PO did some "engineering" that was shoddy :(

OK, that makes sense now. I'm pretty sure that hollow screw is present, but it's either not screwed in properly or it sheared off at some point.

That much I assumed. The PO had a tendency to do that. Fortunately not for anything major, but there are similar levels of hackitude in other parts of the car.

I had this issue before - needed to get a 12pt. triple-square socket from Snap-on. This is a solid socket, so the wires will have to be unplugged prior to snugging it back up. Make sure you label the connections so that all directional functionality remains the same.