it is a very good product, but expensive and hard to get it to look good in the trunk. an easier fix is the spray-on. as the name says, it just sprays on and it does the same job as dynamat if not better. also, make sure all the screws in the trunk and near the trunk are tight and you dont have a license plate cover or cheap motor antenna. you may laugh, but my bumper has to be screwed back in about once a month.
you could go with edead fatmat second skin theres a couple others but i forget dynamat is just the most expensive i dont think it is the best i have edead v3 havent put it on yet but heard it is one of the best and cheaper than dynamat