i spent about $100 in sound deadener to do the roof, 4 doors, and back wall of my truck with about 50% coverage (40-50 sq ft), more in some areas. crew cabs are a little bigger than ext cabs though, two 36 sq ft packs of stinger roadkill on amazon is less than $200 and i guarantee you'll have some left over if you dont overdo the deadener where its not needed