I have m performance exhaust ~ on my M3.
But after 5000miles of driving the m performance, ti muffler developed
a crack on one of the exhaust pipe outlet area.
Luckly it was replaced under warranty.
Too bad for the state of the art manufacturing process. It was a huge problem
which BMW never placed a recall. Over fifty FX M3 M4 cars with M performance
Ti exhaust owners experienced this and were replaced under warranty.
But I love my M performance exhaust ~ Love the Sound and quality.