I spoke with my contact at Magnaflow about your 2007 Infiniti G35 Coupe. They told me that the Stainless Steel Cat-Back Exhaust System, part # MF16641 is not much louder than the stock system it replaces. They told me that there is a small change in the pitch but an insignificant change in the noise level. This system is designed to increase horsepower and torque and is constructed of stainless steel.
They also told me that this system weighs quite a lot less than the stock system installed... view full answer...