Im not familiar with the new trucks but have had a similar experience. Bought my wife a new 05 Expedition straight off of the lot, after a few weeks she wanted a bug guard on the hood and some other goodies so we did get them and installed them. About 2 wks later I rode with her to town and at highway speeds could hear a loud whistle and something vibrating against the front of the cab, long story short, the bug shield changed the aerodynamics on the front in such a way that the valence where the wipers are was causing a whistle and vibrating very fast against the cab at the bottom of the windshield. I removed the bug shield and have never reinstalled it but the whistle and vibrating disappeared immediately. If you have added anything on the truck it could be disrupting the airflow when the conditions are right.