Dynamat or Fatmat??

thanks for the advice, since I have the interior stripped in my car I might as well add some sound deadening material. I have two 10" subwoofers in the trunk, and no, not for rap, I just like floor pounding double bass. There was some significant vibration when it was sitting on just carpet. I'm also hoping to hear less exhaust because it is LOUD inside, especially on the highway. i guess using this kinda stuff is really the way to go.