[sick472]

Dynomat does yield some sound insulation, but it is mostly to stop the vibrations of "loose and free" sheet metal. eg. Take a dummers cymbal and just put a piece of chewed gum on it somewhere...it makes a big difference. The gum dampens the cymbal's vibrations hence killing the sound. Your gas tank already has the chewed gum in it in the form of gasoline. A better solution would be closed cell foam, carpet, cardbaord, or even some bubble wrap. Adding dynomat to will help a bit, but not as much as some ohter things. Carpet would be on the top of my list to try.

Me...I dig the sloshing.