Yesterday, I took my Z to the muffler shop. I had them remove the rear muffler and the center resonator. I place of all that they installed a Magnaflow muffler where the resonator was and straight pipes to the tips where the muffler was. Man it sounds sweet! It sounds just right! Everything including the muffler was less than 1/3 the price of a Supersprint or Eisenman. It sounds louder than the Ikon muffler I had on my E90. The sound is not annoying and it doesn't drone. I may post a clip and pictures today when I get back home from work.