I am looking for ways to quiet my diesel beast... I have heard that wrapping the exhaust can help.. and this makes sense since it seems that most the sound propogates from there rather than the engine itself because the engine is so dense. So, has anyone tried this? If so, how much did it help with noise reduction and how much did it cost for the wrap itself? Also.. I have noticed that when my truck is running and the engine vibrates the exhaust pipes rattles against the metal rod apparatus which holds the exhaust in place. Was there something originally there that held the exhaust in place between the metal rod pieces and the exhaust that was removed or worn out at some point? Some type of hard rubber pieces or something?