Here's the problem. 99% of the people who install these aren't aware that there's a an adjustment for the catback hanger that moves side to side. Every car has different tolerances which is why this adjustment is in place. Even the OEM tolerances aren't perfect, which is why the adjustment is there.
I've returned a few sets of downpipes for "rattling" and I've test fitted each and everyone on our shop car and while there is the occasional dud, (3 out of the 308 we've sold), the rest fit perfectly by adjusting that mid pipe hanger. You can remove the heat shield which I've had to do with plenty of the big $ downpipes or you can adjust the mid pipe hanger. There's usually a few ways to fix the problems, it just requires the knowledge/experience to do so.
Any 3" downpipe is going to rattle if it's not adjusted correctly. There's just not enough room in there to bolt the DP's up without clocking them correctly first.
The first time someone installs a set and it rattles, they generally post about the rattle, then I reply with the appropriate corrections and then the rattle is resolved, yet the it never gets posted publicly so when you see people complaining about rattling, you have to keep in mind that in most cases the problem is solved & you're just not seeing the response posted. There's also the instance of the downpipes enhancing the sound of the wastegate rattle which the untrained ear won't be able to differentiate.
Whether it's fitment or installation, we're more than happy to help customers with their installs and we stand by our product 100%. Rattling/rubbing/touching is not an acceptable standard to us and it's not how these downpipes are meant to be installed.
If you're having trouble, shoot me an e-mail and I'll be happy to help
