Iv got £2300 worth of ice, well 2x amps and 2x 13" subs.
I ran the set up all FOCAL with dsl speakers front and rear with out sound deadning and it sounded sh*i to say the least, my car rattled like a bit*h... my boot the doors the lil spoiler thing with the break light on, even the side bump strips where rattling,
i booked it back in within 3 days of having the system to get all the boot under the carpet, the sides the inside of the boot lid and under that little spoiler thing. and over £400 worth off dyna mat just in the boot, i have to dyna mat the rear quarters and behind the bump strips, i play my subs on -12 and they still make my speakers in the rear rattle, if your just running small power then i would bother dyna matting personally save you money, but if your like me and have a problem with little rattles then go for it, although youl never lose all of the vibrations, i got an anoying rattle coming from where trhe light is, and my heat shield really rattles, its all good tho!