Unstoppable Trunk Rattling?

It will more than likely get rid of nearly all the vibration and rattling from the rear of the vehicle.  You'd be surprised at how effective that stuff can be when it's properly installed and sufficient amounts of it are used.

But just out of curiosity, what kind of car do you have?

Not bad at all, doesn't really look too purple to me.   I'd take that car any day!....lol that is, until my G35 gets built and shipped here from good old japan (3-4 months they're telling me!!!!)

Let me know if you ever need any pointers on the dynamt or whatever installation, but it is really a piece of cake as long as you're patient.  One thing I REALLY recommend though...if you install the dynamat extreme or any other product with foil backing, before doing the install put on a pair of mechanics gloves or just plain old latex gloves.  Anything that will protect your fingertips.  You will prevent all kinds of nasty cuts that occur as you use your fingers to smooth out the dynamat and press down the edges.