Hi dw069,
Mine suffered from the same and I have to say I hated it.
With the info from various members here, the spring sagged over time was clear, and the only way to fix it will be to get a new spring, or to use Passat spring with mods.
I was a bit against the idea of having the spring modified at the time, cut 2-3 rounds, so what I have done to my G Syncro was to put a spacer hub between the lower seat and the spring itself.
I wish I could show a picture but I do not know how…
Can someone show me how to attach??