I bought acoustic insulating foam from McMaster-Carr . . . but haven't had time to install it yet since I'm just finishing installing my new upholstery.
I ordered 8' of the 1 inch skinned adhesive-backed. It has the highest noise reduction coefficient. Specs say adhesive is good to 225 degrees.
"For every complex problem there is an answer that is clear, simple, and wrong." (Henry Louis Mencken)
2005 X2, Viper Red, MCX, Acme 1285, PPass, rear 750 sacs, KGB, IBS
(previous) 2001 X5, 1991 TriStar 190