ek4 sunroof rattle, fixes?

[vinnY]

okay so car's getting old and rattles and showing up here and there, easily fixed by tightening screws or replacing clips

the slidey bit for the sunroof however seems to be rattling when pulled all the way back
short of ripping off the roof lining and checking it out, anyone found any remedies which might fix the rattle?

[Limbo]

black silicon :)

[vinnY]

but it's a moving part?
the sunroof itself isn't rattling, it's the slidey cover thingo(mdf?) that's rattling