I have new to me a 2010 G37X that ifI get it up to 100 kph (60mph) I get a drone in the car seems to me its coming from the back. IT gets loudest at 110 kph and then seems to taper off above 120 kph. I lifter there rear wheels and spun the tires and the bearings seem to be quiet and smooth. I do not get any vibration from the car.
Very annoying. Hopefully someone can help. Im at a loss
The sound is like a low exhaust rumble. I did shift gears at speed and it’s not exhaust or engine. Even under throttle as you pass that speed it is there not just at cruising

Often issue with aftermarket exhausts. Do you know what’s on it?