RE: Sound Deadening and Insulation
I've done almost exactly what Jeffery has done using the same
material.  The sound deadening works great, I have it everywhere
except behind the 'frig, that comes next.  I've also made thermal
blankets using the same material for my windows and as an outside
cover over the refrigerator when camped for any period of time.  One
difference, I used rare earth magnets duct taped in place to hold my
insulating blankets.  That works great BUT the tape turns gooey and
detaches under the heat.  I just ordered a bag of the suction cups
Jeffery pointed us to (thanks Jeffery) and will replace the magnets on
some of the blankets that have given the most trouble.
BTW, a 4 foot wide roll of the thermal material (trade name Reflectix)
is perfect for making a thermal blanket for the pop-top, several of
the WetWesties have done that and report very good results in keeping
in the heat when camping in cold weather.