I did a custom exhaust system because every time I contacted or called about the GT-R I was put on hold and no one would answer the questions I wanted to know. Same goes for through email so I got fed up. Also, I live in MO and they wanted almost $800 (even when I had a $100 discount for being a member). Didn't find this fair at all. I paid less than $400 and I got the exact same muffler. Its a Magnaflow Camaro muffler and I got 3 1/2 tips. Only thing I didn't do was a full system. The stock resonator is still on because I was afraid of the sound. It sounds really good the way it is but maybe I should replace it with new piping..