So I have taken to deadening little pieces while it’s quiet in work, so today it was the turn of the b-pillar trims, for a bit of fun I weighed them before and after, the polystyrene piece was removed, deadened underneath and then spray glued back, where the seatbelt sliding section is I added some patches of spare Milano suede I had kicking about, purely just to put something soft and thin between the plastic slider and the pillar trim
i also added a few strips of the suede around the bottom where it comes in contact with the side sill trims, and also individually wrapped the three clips on each of the lower trims
the result... 580g to 952g, a good chunk more trim that should stand less chance of resonating