Electric window problem, rear N/S

My winder cables are fine, and I have a new (VAG) nylon connector clip for the slide,

BUT a): I can't compress the springs enough to give adequate free cable to pop the ferrules into the connector.

: How do I connect the galss bracket to the nylon connector? I have a small white nylon clip which came out of the old cheap plastic connector, but can't see where it goes.

Am I missing a bit? I think I may need a modified glass bracket.

Any help greatly appreciated, many thanks in hope!