I have a Borla CatBack system in my truck. I had it installed at 700 miles (35k on the odo now) The shop had to makeup a 8" piece of pipe with a flange and slip coupling that installs between the borla flange and the end of the cat. On earlier model X's there was a flange at the end of the Cats. On the 04 its just a slip coupling. No problems with the system so far but im sure that the 8" piece that was made up will fail in the future, (its galvinized)The Borla system is stainless.