Spent considerable amount of time and $$ in locating then upgrading the two side door mirrors. They now look very nice, but any amount of road vibration allows the glass to move around in the frame. Can't see what's behind me very well. Bought new glass from AA and also obtained the best to be found gaskets. After 45+ years they aren't as supple as new. What to do ???

Interesting,
There should be a plastic piece that holds the mirror behind the glass is that missing?

Mine vibrates too. Maybe not as much because I can still make out the image of cars behind me. Amazing how much image processing circuitry humans have built in.

My only thought towards solution is that perhaps the door skin is moving?

I can see that it could be a mount issue, but I'm betting that the piece that should be holding the mirror is not doing it's job. I would think that if there really was amount issue you could tell if it was loose. Perhaps the gasket on the mount has hardened? I'd be happy to throw you one if you think that's it.

Mine does the same thing. It's OK during the day as I can tell if a marked police car is coming up...but at night all I see is a headlight blur. I would like to fix it someday but I've been living with it for 7 years so...

The glass should not be loose in the frame. The plastic retainer shrinks with age and exposure to sun. Right before it cracks and disintegrates. Definitely a need for these Mark.

Here are the correct spacers for the early and late mirrors. If mark needs them for a template, I'm happy to send them,. Aong with glass, I need about 10 of the early ones and 5 of the later ones - I have a bunch of mirrors sitting in a box waiting on these parts.

All the pieces are there just old. Bought new, acutally old resold stock, from AA for the gasket. It does have the plastic holder in the background. Very annoying

Is the glass the same thickness as oem? 3mm

I would agree that is the parts were the correct size the glass could very well be the issue. I can looks at making the holder from silicone and slightly thicker. It could accommodate the glass variance. I'll guarantee that glass is not 3mm.

Measured AA glass at .087" or 2.2mm thick. Fix glass thickness or a newly sized gasket/holder. Where too from here...................

Perhaps a wad of butyl behind the mirror ?

How about a 1/32" sheet of rubber behind the glass, which is darn close to the 0.8mm thickness you need? Found this one on the Wally World site.

Do you mean the oem glass or AA?