I'm not saying you should, but I have used low expanding foam in the trunk lid.
I would guess most noises you hear are not from sheet metal. Anything loose, cables, even wires not in a loom, seatbelt retractors are a ***** to tame.
I would guess most noises you hear are not from sheet metal. Anything loose, cables, even wires not in a loom, seatbelt retractors are a ***** to tame.