That's called a CLIP GLASS HOLDER, they vary between models so it probably either part no: ALR6219 or AWR7092 (which same as STC4787), I dunno if there are any more types. They cost less than £3.00 each. Search google for those part numbers, lots of online supplier, some give the VIN numbers for the models.
I think there is supposed to have a semi hardening pad in there, like tacky putty to help grip glass. It is tempting to use epoxy resin to glue the cradle to the glass as a repair but that would make life difficult in future if ever need to remove mechanism. I have used very tacky putty in there to renew the grip, has worked for over month so far without the glass coming out and falling down inside the door :roll:
