hey.. got my good ole 2000 s80 t6 making some noises... everytime over a speed bump it sounds like a large spring is unloading in the trunk.. did find that the battery holder was left loose and missing a bolt.. and when i hit it the sound was as exactly as the noise that i hear on the road.. but after repair and a test drive it was confirmed not to fix the noise.. im starting to go crazy.. shocks seem to have good recoil. no loose sway bar links or anything.. any ideas?