Chalk this one up to noise and weight reduction. I was getting an irritating vibration/buzz from the rear at certain rpm's. Thought it might be coming from the thin aluminum "heat" shield in the back. Pulled it off (3 bolts) and the noise was gone. It probably only weighs 1 or 2 pounds so don't think it's good for real weight reduction. Also my SLP tips are probably 1/2 inch from the rear outlet plastic with no signs of melting so I doubt that this will affect the plastic on top of the exhaust seeing it is about 9 inches away. (Chalk that one up to GM overengineering) This one is for the '04 guys, I don't know if there are 2 for the 05/06 guys or not. I'll leave the other shielding on around the cats though. ;)