I had a flowmaster 40 series put on mine, with no rattle. I didn't have the kit, so I can't say much for the fitment problems. I've had the muffler for about a year and no rattling what-so-ever. I've heard from several people that their Flowmaster kit was great, fitment was good, no problems with rattling, perhaps you just got a bad one out of the bunch. I believe the kit comes with a 50 series muffler, the 40 series is a bit louder. Flowmaster is probably one of the best mufflers I've heard on a PT, sorry yours didn't work out so well.
Summit may help you out, doesn't hurt to ask them.
__________________
|