In a ongoing search to lessen certain road noise I have done this mod to my window shrouds. I lined the inside of the shrouds with "speakerbox/automotive trunk liner" I purchased this for some other projects at http://www.yourautotrim.com/trunklining.html
. I had some left over to do the project but I would think a yard would get through all four window shrouds. The first step was to cut strips of the trunk liner to fit the back side of the shroud. I then applied spray adhesive to the back of the shroud. I would trim overlapping pieces, but the main concern is to keep the edges as smooth as possible.Once dry you trim around the outside edge of the shroud with a razor blade.
Ready to trim
I also added a plywood stiffener behind the window shade attachment screws, also wrapped in the same material.
All back on
All in all I am pleased with the improvement, and it is a pretty easy mod.