I've been meaning to write this post for some time. I was one of the early adopters for the 981 Fabspeed headers and 200 cell cats. For most of the time I had them, I was very pleased with them. I got tons of compliments on the sound, and I appreciated the slight bump in mid range torque. Unfortunately, the cats only lasted about 16-18 track days. Fabspeed notes on their website that their warranty won't cover sport headers if they are used on the track, but the way the upgrade is discussed in the forums, I'm not sure most folks are aware of this. I don't think this is specific to Fabspeed either. They were nice enough to take backs the cats and weld in a straight pipe at no charge, essentially turning them into race headers. If anyone is interested in the race headers, send me a PM. I'm retiring my Cayman from track duty after 35 mostly problem free days (moving to a GT3), but if I was continuing to track it there is no way I'd want to deal with the hassle of replacing the Euro cats that frequently. Since all auto manufacturers in the US must warranty catalytic converters for 8 years, I'm less concerned about burning the stock unit out. So if you're planning on tracking your car, think twice before buying something with an aftermarket catalytic converter.