So I just recently purchased a 04 G35X while I was home on R&R from Iraq, so I have no clue about the engine... well anything about the car. I went from a barebones Wrangler to this... lol Anyways... I'm looking to replace the exhaust and really like the soundclips Ive heard of the Borla Exhaust system... Does anyone know the stock number for the muffler itself from this particular system? Also Ive read the one post stating if you utilize the HKS muffler then to replace the resonator with one from the coupe to make it sound better... what is this resonator? does it improve anything other then sound, if I end up just buying the muffler and not an entire exhaust system? Like I said I am completely new to this whole car modification, let alone an Infiniti