In my '94 I placed dynamat between the door and the bracket for the speaker, and then again between the bracket for the speaker and the speaker itself. Honestly, there was not a noticable difference with just that. It was when I covered both the door and the door panel and the rest of the surfaces of the truck with 1 or more layers of dynamat that I noticed a difference, and a big difference at that... Mine is now like a tomb at highway speeds (65 miles/hour). And when I had my system, nothing rattled.