That's a strange one. Those parts shouldn't really have any bearing on the top mounts, but that's how it goes with uprating things. The next weakest link in the chain starts to make noise or wear out a lot faster.
Springs don't make a difference to the top mounts as those forces are supported by the car body and the big fat bearing. The bit that squidges is the inner part of the mount the damper rod bolts onto. The factory dampers are less aggressive so you don't hear anything, but with aftermarket uprated dampers, there's a lot of movement which is really noticeable with standard GTI mounts. A lot less so with TT ones.
I noticed the rubbery squidging noise the most over speed humps. The TT ones still do it, but way less than the GTI ones. I could hear those squidging going round corners as well!
