I will have a tutorial started on sound deadening soon, I specialized in it for 15 years and figured a few things out, especially cost effective, low weight, area by area what needs done and what does not need done. I shipped tens of thousands of packages around the world before I retired myself from it and have had many win championships in sound quality using the products and my methods(more intense for audio comp but not needed for a street car unless the main goal is audio over anything else.