I've noticed in my Model S (Dec. 2016, 75D) that around 80 mph the wind noise makes a big jump in volume and seems to change its sound characteristics as well. It's so pronounced that when I first got the car, I thought there must be a body panel that was loose somewhere, that was either vibrating or catching air. The sound seems to change from the same low hiss that it has from 0-75ish mph, to a dull roar at around 80 mph (depending on which way the wind is blowing). I'm curious if other people have this experience too. And if this is a regular and well known problem, then does anyone have any idea what the source of the noise is? Given that it happens at such a specific speed, it makes me think that there's some part of the car that has great airflow until around 80mph but as you approach and pass that speed, the airflow gets disrupted and becomes very turbulent, or maybe airflow stalls in one place and in turn causes buffeting in another, or maybe it starts vibrating a panel, or maybe there's some space under the car that acts like a tuned port and the air mass oscillates at those speeds (and above as far as I can tell). My main motivations with this question is a) is this true for all MS's or just mine? and b) if I can find out what the source of it is, then maybe I can install some vortex generators and/or some other kind of modification or hack to get rid of the noise. Unlike most road noise in most cars, this one seems to make a very definitive and distinctive transition at a specific speed, and that makes me think it has a very specific cause, and that makes me think we can fix it. I'd be very grateful for anyone else's experiences related to this. Or in an ideal world, if anyone has any access to, or knowledge of, the wind tunnel testing that Tesla did, I have no doubt that this condition is a well understood (by the folks who did the aero work). If there are already resources or threads that cover this topic, please point me there. I've been looking for a while but haven't found a really good discussion about it. Thanks!