When I mention that I installed DynaMat in my souped up 2001 Mustang GT, I normaly get intresting feedback because until here recently I've been rocking my stock stereo and speakers. The road noise created by the performance exhaust system, stiffer suspension, and wider tires is enough that I just never worried about music quality. So, why did I install it? Installing Dynamat in the floorpan, doors, back quarter panels, rear shelf, trunk, and trunk lid (all done with one Dynamat Extreme Mega Pack) has reduce the internal noise level in my car by what I estimate to be 40%. My wife was amazed the first time she rode in the car after the install. She was excited that she could enjoy a fun ride and be able to have a conversation without yelling over the car noise. Now if Dynamat could find a way to keep the noise out while the windows were down, I'd be in heaven! Now that the road noise is reduced so significantly, I have started playing with sound system upgrades.
Suggestion: Invest in a good quality roller instead of a cheap one, a good blade to cut the pieces with, and a heat gun. I started the project without any of these and quickly realized just how valuable they were. It may add a little more to the cost, but trust me, all of it is worth EVERY PENNY!
Pros: In a normal car, it would sound silent in your car, in a throaty sports car it reduces down the noise so you can enjoy the power without comprimise!
Cons: Death by a million cuts. LOL Installation will result in minor cuts in your hands nomatter how carefull you are if you're not wearng gloves!
Also, installation on a level like I did will require a full weekend. You'll want to strip the interior of your car out to do the job right, and you want to do the job right. It's not a quick fix.