hey, I have a question for you all. I am buying Dynamat extreme to put throughout most of my car. I was wondering if i should get the economy roller(hardwood) or should i get the professional roller(solid rubber). There is a 10.00 difference in the two, but i would be willing to pay the extra 10.00 if it makes that much of a difference in quality and time. Also do you all have any tips for installing or best places to put mulitple layers? thanks.