I have a 2015 Explorer and noticed a vibration noise coming from passenger windshield area at 70 mph. It sounds like a bee buzzing. I let my Ford Dealer know about it, but they stated that the issue had been resolved re. pillar clips on previous years and the 2015 should not have any issues with this noise. I checked this Forum and found out about the rubber cowling vibration where the cowling meets the windshield near the wipers. I checked mine and it was not resting securely against the windshield which appeared to me to be capable of causing a vibration at high speed ( much the way a strap will vibrate when subjected to high wind). I'm going to pick it up now and will post to notify if the problem is resolved.
UPDATE: Just picked up the Explorer and the new cowling is in place. The new one fits much tighter against the windshield and so far I have not been able to duplicate the buzzing noise that I heard previously.