I have the same
problem on my Seat Arosa S 2004, went to the dealer and they said that it was a known
problem. I put a bathroom washer in gap between the centre panel, and the left dash. I pushed it in so that it would act like a wedge. I cut the top off (so you could not see it). Also I had to be very sure that it did not drop inside the dash. But, that rattle/creak was driving me crazy
It is still working today.