I can hear the exactly same noise you guys discribed. It sounds like I am oprating a jet or I have a turbocharger in my car!
I own a g35 coupe and drove many g37x before, never heard this noise tho... I am going to bring my car to the Nissan dealership again. But before I walk into their door, is there any offical fix for that? Or haven't Nissan confirmed it's the ECU? Fuel pump? Diff? Or my ear problem???
If dealership can't fix it this time, I will have to install HKS Hi-Power catback to eliminate this problem.