I have recently started having this problem as well. I got brand new tires about 3 months ago, no problems until about a month ago. The tires are fine and this problem only happens at 45+, but only once in a while. It's not balance, I've had a variety of balance issues in other vehicles and those are all noticeable and reproducible. This vibration only occurs at speed, not when braking...brakes are fine, no warp, smooth... It definitely does it on road that is really smooth, like fresh paved freeway and new roads. It has me stumped and I don't want to take it to the dealer (2016 still well under 5 year/100K) unless it is wayyy more reproducible.