not sure if this is allowed.. Amazon has automotive sound deadening material really reasonable. Brand name is Noico. 36 square ft for $63 . If you are a prime member shipping is free, the stuff is heavy. Material is really easy to work with, coforms easy to shapes. Hit the dollar store for poster board for patterns. Stuff can be cut with harbor freight scissors. use a formica roller to cinch it down. You can use aluminum self adhesive duct tape to seal the seams. Best advice I can give is to take your time.
