I put my prescription sunglasses down on top of the instrument panel, a screw had come loose and a lens fell out. I went to pick it up and it disappeared down a gap between the back of the panel and the windscreen. I cannot see it from the outside because that part of the windscreen is black, I cannot see it from the inside because I cannot get close enough. Attempts to get it out by poking things down where it went have all failed so I need to buy a new pair. I have never seen a gap like this in any other car, the back of the panel will be flush against the windscreen. Is my panel or windscreen not fitted correctly or are they all like this?

Mines like it too, you can buy a rubber strip that fits in the gap to stop it.

Google "Dashboard sealing strip" and you'll find them, you can get them very cheaply from the likes of Temu & AliExpress (~£2-4) rather than the £10+ on Amazon.