hum

I've recently upgraded my 2013 MS to a 2016 model, and noticed that the new car always seems to have a hum while parked in the garage. Doing some searching revealed that it's expected that there would be some humming due to coolant circulation and such, but I don't think it should be lasting...

So, I'm developing a new problem since a few weeks.. Between 120 kmh and 130kmh (75-85 mph), I have a hum that is quite apparent. It disappears as soon as I accelerate hard, but is there all the time when cruising at highway speed. Now I've read on the German TFF forum that I'm not the first to...