The difference this makes is like night and day, get the most out of the actual components by purchasing this. There are generic brands, but why not just get the real thing. I used 2x36ft packs on my 2002 Monte Carlo SS. I wish I took measure to additionally reduce the vibration of the door panels. I had to set the Xover on my door speakers to 320 high pass because the vibration was rediculous. I think the max excursion from the speakers I chose may be causing the speaker to touch the panel itself. This product may reduce the flow of air in and out of the vehicle, my black on black car gets hot enough to roast nuts. It was winter when I did the install, a 125,000 BTU heater helped make the pieces more pliable (dont light yourself on fire). I got an experienced body man to help me do the install. Dont let an area that is hard to get stop you from thorough coverage. Doors, floorboard, trunk, and if you're really throwing money and time at it, the roof. You know how bumper stickers have a division in the backing? Make a cut like this so you can use a whole sheet, but stick only a protion on at a time. Videos on youtube may be helpful. Worth every penny, but the generic brands may be worth saving a few pennies on. I plan to get the dynamat foam pad thing for the trunk lid later.