as per our rather lengthy chat
The bushes above, available from Mazda, are only 1 out of 2 types used in these windows, and there is only 4 of that type [really weird as they come in packs of 5].
To replace that bush:
wind the window down.
remove the two window stoppers held on with 10mm bolts.
wind window up past the door frame, then tilt the window forward exposing the bush.
the bush is held on using a bolt through the middle and washer on the back of the window.
using a Torx attachment and pliers undo the washer and the bush comes off.
then just put it back together.
try to align the stoppers in their original position, otherwise the window wont close properly.
if there isnt a bush, bolt or washer there, check the bottom of the door; they often fall out
i will try to get some pics of this process and upload them, there was a guide on here and Club323F on how to do this, but the pics dont work anymore