All, I have posted about every aspect of my install except for this one. I have a 2008 Cobalt LS Coupe and have very recently, 1 Hour ago, bought a new set of speakers for the doors. I have never deadened a door before an am looking for information as to where the best locations for each type of deadener would be and if your regular "sound mat" would be good enough. The picture below shows what my door looks like with the interior panel taken off. Any help would be much appreciated!