A while ago I purchased new front, back speakers and head unit for my car. The deck and front speakers are installed with no problems, and look and sound great, how ever the back, 6x9 speakers, which I placed on the narrow bit of the back shelf (that lifts up when boot is opened). I reinforced the shelf underneath with wood about 1 inch thick. The problem is that even with the shelf being reinforced, it rattles and shakes when I drive, causing distortion to the back speakers. Does anybody have suggestions as to how to and where to place the 6x9 back speakers, so they are stable? Front speakers: 6.5 inch Coaxial Phoenix Gold Back speakers: 6 x 9 Phoenix Gold Deck: Pioneer DEH - 7750 Ryan :)