thanks info was awesome.dynamat extreme is actually one of the best performers on the market, albiet it is the most expensive. so if you can get it at that price, you **** well should.
and on top of that - a BIG rattle killer for the civic trunks - one that i did to dtours trunk. is loosen the two bolts that attach the trunklatch to the edge of the trunk compartment. you know, that U shaped metal hook that the trunklid attaches to. theres two bolts on each side. loosen them and push the latch hook down away from the trunk lid and re tighten. it should only move like 1\8 inch at most, but it will seriously tighten the trunklid to the car more and kill a nasty rattle when theres too much pressure the actual latch will bounce on that hook causing a terrible buzzing on the outside of the car.
but yes, i would use dynamat extreme if i had the luxury.