[.:4:.]

So provided nothing is loose, the cheap solution I can think of is sticky back door foam/insulation. My first car I spent my budget on the system then had to cheap out on the rattles so it was door foam sticky backed to the door cards and cheapo under bonnet sticky back foam for the parcel shelf. It worked pretty well for what was an oversight. The door stuff is a bunnings home style thing. The supposed to be bonnet insulation stuff was a jaycar purchase. The car had enough in it to create rattles. 2 amplifiers and maybe a little bit going on in the boot.