Sorry to bring up an old thread but I just wanted to bring to light something about the install. It is extremely easy to screw up the threads on the cat when removing the original exhaust. I am always careful to avoid cross-threading and try to take it easy but I wasn't expecting it to be this easy to to mess up the threads. Especially during removal!
Usually cross threading happens when putting the bolts back in. Not the case here. I lined everything up and carefully began bolting the new exhaust in and the bolt just stopped dead. There was nothing I could do after that. The top bolt on the cat was no problem. Now I need to go a shop to see if it can be tapped. Just a warning for everybody. Maybe best to get the dealer to put it in.
Other than that this exhaust is fantastic. Andrew from Active Autowerke hooked me up and it is worth every penny. I was thinking of going with Corsa but for almost twice the price, no way. There is no possibility of the Corsa exhaust being twice as good. The sound of the Active Autowerke is definitely deep and mean with the N55. Not too loud either. When cruising without accelerating it just barely gives you the impression that something special is there. When you roll on the throttle it wakes up nicely and sounds about twice as loud as stock with a better tone overall. It's perfect in my opinion. I didn't get high up in the RPMs yet though since I bitched up the one bolt.
Now the downside. There isn't much. The rear mounts are reused from the OEM exhaust and there are long rods that get installed into the old hanger rubber mounts. The mounting for the rear of the exhaust is just a bit clumsy overall. It moves around more than the stock unit but it's not bad and maybe I did something wrong too. I was getting jacked near the end due to the cat bolt problem.