Odd one this,
I left the house yesterday to walk to the shops and noticed that someone had lifted up the nearside wiper and a mirror was lying on the screen. I haven't used the car for a few days so it must have just dropped out, or was bumped by someone but they would have has to be deliberately walking along the grass verge and not the pavement.
Luckily the car was half way up the grass verge so the mirror didn't break and some thoughtful person had seen it and put it where I could not avoid seeing it.
When I looked more closely it was the glass from the nearside door mirror, but even more oddly it is mirrored on both sides.
The backplate on the door mirror didn't feel sticky at all, it's as if the mirror glass was pressed into some sort of hot plastic that cooled and grabbed the glass. Now it is just smooth black plastic with a slight lip marking the outline of where the mirror was affixed. No trace of adhesive on the mirror side that was embedded.
Now the question, what to use to stick it back on ?.
I think I will use some fine abrasive to score the mirror side that sticks onto the backplate.