sometimes i wish i had bought shit seperate, but then i remember how fucking much of a pain in the ass it was when my friend did his shit and it was all pieced together, piping didnt fit right and they leaked like a champ, had to run back and forth to get this and that, if you want a prety much hassle free installation, get a kit, if you dont mind having your car down for a couple of days to get pipes welded and shit, buy shit seperate.....