I have about 123 sq ft of
RAAMmat in my Xtra Cab.
Single layer on inner and outer door (15" square triple layer behind speaker).
Triple layer on inner Xtra Cab panel (this area resonated a lot).
Double layer on back cab wall.
Single layer across the entire floor (double on transmission hump).
Single layer on both top and bottom of rear storage area metal.
Misc. pieces on the rear plastic panels and rear plastic speaker mounts.
Everything was also covered in ensolite.
I also used a liquid based deadener on the the back cab plastics and front door panels.