Whenever you open or close the trunk you are changing the electrical characteristics due to inadequate grounding of the lid. Install a ground wire from the trunk lid to the chassis. Also ground the amps and any other metallic part of the sound system.
And don't asume the threads of a sheet metal screw are an adequate ground. Use grounding washers and grind the paint off where the washers sit, then prime and paint over the tightened screws.
2005 4.0 MT dual exhaust GT mufflers GT suspension and wheels