I did quite a bit of research before deciding on Dynamat.  There are some cheaper competitors that people swear are just as good and they may be, but I just don't trust them as much.  If you do your research you will even see that some people chose to use roofing material that you can buy at Home Depot.  Someone would have to be OUT OF THEIR MIND to put $20 worth of roofing tar into a $20,000+ vehicle.  The only negative thing people have to say about Dynamat is that it is priced high, but if you buy the bulk packs on Amazon you will save yourself a ton of money and is actually a pretty cost effective solution for DIY work.  I have looked around and Amazon has the best price anywhere.Main competitors and my impressions of them.  I have not purchased or used these product, but this is an idea of why I chose Dynamat over them.  I am not a car audio professional by any means.  This is the first time I used deadening on my car and I am writing this to help anyone else who is thinking of doing this.1) RAAMAudio RAAMmat + Ensolite Foam - Most cost effective &#34;legitimate&#34; option.2) Sound Deadener Showdown - &#34;CDL Tiles&#34; + Mass Loaded Vinyl.  SDS would be an interesting choice.  If you look through forums you will see some people who really like this stuff, but I found the website to be confusing and I could not truly make an informed decision one way or another.3)Fatmat:  Cheapest of all automotive dampeners, but one Google search of &#34;fatmat smell&#34; is all you need to know.  Some say it smells awful and some don't, but there is no chance I risk it.  This stuff is super cheap, does not deaden as well as competitors and stinks.  I would use home depot roofing material before this product.  Move on.And to the &#34;REAL&#34; competitor.4) Second Skin Audio- Damplifier Pro + Closed Cell Foam (CCF)-  Although I decided on dynamat, based on reviews and forum comments, I think that Second Skin Audios product line may in fact be superior to Dynamat, but I decided against it for a few reasons.  Damplifier Pro is a good bit heavier than Dynamat extreme.  For most, this isnt going to make a huge difference, but I am lining a performance car with more emphasis on performance than sound.  I want an improved sound system, but if the increase in weight is only going to improve things very minimally it is just not worth it to me.  A lot of people say that Dynamat is the most expensive, but a 36 sq. foot pack of Damplifier pro costs $204+ shipping.  They do have some coupons occasionally, but it is more expensive.The fact is Dynamat is proven to work and is trusted by professionals.  I do not think you can go wrong with Dynamat because the only bad thing people have to say about it is that the price is high which is a bit of a myth.  If you drive a big truck or SUV, want the absolute best sound and aren't as concerned with weight, I would think about the 80sq foot Damplifier Pro shop pack and CCF foam.I turned my trunk into a enclosure with Dynamat Xtreme.  I lined just about every surface, doubling up in a few critical areas and was able to line my trunk with this kit.  If you want to really go out and line an entire car, you will need 100 sq ft+ of this stuff.  If you are doing the trunk and doors like me, you'll need 50-80 sq feet depending on whether or not you plan to cover the entire door.  I would use the bulk kit for anything but the doors.  You can surely use the Dynamat in the bulk kit on the doors, but the door kit strips 12&#34; x 36&#34; and make for a cleaner install because they will run the full length of any door.  It would not be the end of the world to have extra, but I would try to make a good estimate of how much you will need so that you arent leftover with a whole box of this stuff.One final recommendation as I try to unload all of the information I have learned.  Dynamat claims that you do not need a heat gun to install Dynamat Extreme.  That may be true, but after using a heat gun to put the finishing touches on the trunk, I would have to strongly recommend using a heat gun for trouble areas and difficult corners.  I was able to put the Dynamat down so much flatter and nicer by heating it up a bit and rolling it down.  it especially helps to heat corners and tight spots where you cannot get the roller in, because it makes it easier to mash the Dynamat down with your fingers.  I am not going to use the heat gun on the doors however, as I believe that there are more heat sensitive components in there and do not want to chance it Dynamat claims it is not a necessity.I plan on using Dynaliner on top of the Dynamat in the doors (and trunk I think) as well as by itself in a few areas.  I really hope this helps someone.  If you have anything to say about my opinions, or would just like to comment on what I have done, please let me know.