I took the card off the back the other day, I finally got around to doing this, I found that there was a rattle inside the safety belt unit which is sealed. Replacements are about ?58 +vat from VW.
Before I do this there is some washers to be added on the clip that the belt slides through as this is loose also and the shroud that slides up and down need some foam.
I am going to kill that cat thats in there somewhere!