My 2018 BMW M240i (manual of course) has a high frequency vibration that occurs between 60mph and 70mph only. The vibration hasn't gotten any worse or better over the last year. I's not the tires or wheels as the same vibration occurs whether the has snow tires + aftermarket alloys or the the Michelin PSS + factory alloys (road force balanced). I finally took it my friendly BMW specialist, J&F Motors, in Shirlington (south Arlington). The owner and the lead tech each took the car for a spin. They both seem to think the driveshaft is the cause. The car has abut 45k miles on it, some of those miles being track miles at Summit Point and VIR. I realize there's no way you can feel the vibration but I'm asking for your experiences. Thanks!