I've noticed lately that whenever I shut my drivers side door the mirror rattles every time, the mirror seems firm and not loose. I found out that the chrome cover is the culprit that's causing the rattle, question is how do you stop it from excessive play between the clips that hold the cover on? You can see the 5 tabs that go into the tab holes in the mirror assembly, which when seated inside giving excessive play causing the rattle. Thank you in advance! Regards, Systemlord.
You could also add some sticky felt from a craft store or use a little rubber cement. Put the rubber cement on the tabs and let it dry then clip on your mirror for a tight rubber insulated snug fit.
Well I ended up using 1/16" double sided sticky tape. It helped the chrome cover to have a good grip, but I'm afraid it's the main mount neck that still rattles a bit. It's better now and I can live with it.
There are 2 bolts holding the mirror to the door. You could try to carefully tighten those. Don't use too much force or you could break them.
It's not that part of the mount, it's the neck area where the mirror neck rotates left to right is where it's loose.
Maybe you should pull the mirror off the door & look at that pivot point. Not sure what you will find though.