Since I was mentioned early on in this thread I felt compelled to chime in. I finally got my car back from the body shop this past Friday. So I left some time open this weekend to put on my new HRE's and the Ztek headers. The wheels look amazing, but that's not what we are discussing here. The header install went fine. Fit was perfect. I will not comment on performance gains because I did not put the car on a dyno. As for driving impressions it's hard to say becuase I've been driving my Allroad for 6 weeks, so of course the C4S feels really strong. The only thing I can say is that it still pulls strong all the way to redline. As for the sound, there was definately a difference once they were on. I love it. The car has a mean growl just of idle, and I think there was a slight reduction of resonance at WOT. I'm not looking to start any arguments or offend anyone who has other products, these are just my observations. Lastly, in reference to the C of O, I don't care whether they are made in the US, Germany, or Asia. I was just being honest in that post on Rennlist and wanted everyone to know what they were going to get if they ordered the Zteks.

 

That is I'm dying right now.