I've used 36 sq ft in my small SUV rear doors and hatch door, then sprayed several coats of SS spectrum on top of it... the first 36sq ft was Dynamat X ( got it for $110 for bulk pak), Got some Raamat coming this week and I noticed it's thinner but I can always double or triple it, since I like 3 layers or so on outer door and atleast 2 on the inside door, but be careful that you don't over do the inside door or you can not get the door panel back on...
The SS spectrum worked wonders on the doors, each must weigh like 5 lbs or so more than a factory door.
See ya!