I have an awesome sounding system 2 Alpine Type R 12s on a MB Quart 1000x1 amp and it hits pretty hard but yesterday just messing around, I played it with the backseat down and it POUNDED almost twice as loud. Tweeter (who installed the stereo) told me that the back seats were pretty solid and it didnt allow a lot of sound through. Has anyone put "port holes" in their back seat or anywhere to let a little more bass through?? Im sure you all know who it is also, it sounds good, but it can always sound better!!