Just hung up the phone after ordering a Borla Cat-back system for my IS. Unfortunately they are on back order and it will be about 3-weeks 'till I get it. Over the phone I was told that the IS300 system is a 3-piece system with a resonator, midpipe and muffler. All made of 304 stainless steel with a one million mile warrantee. I figured if Borla was good enough for Team Lexus, it's good enough for me. The race system replaces the catalyst with a straight pipe, probably includes headers too, forgot to ask.