My buddy did this mod to his OEM M3 exhaust, except he had them cut out the perforated pipes and weld in solid pipe. The car sounded like a beast. It was also loud as f_ck! Although the sound was amazing outside the car,
the drone inside was so bad under 3,000 RPMs it would literally make your ear drums itch. I'm not sure you would get the same sound, volume, or level of drone from the N54.