Terrible noise at speed - occasioanlly

[GML]

Seeking help identify an occasional noise, a racket actually, which comes on above 40-45 mph and is NOT associated with any settings of the HVAC system. To me it appears to come thru the center dash vents but I suspect it is an 'at speed' wind buffeting of some part of the windshield cowl and inlet air filter area. I have confirmed that the cowl fits tight against the glass and all parts of the filter and cowl are tightly secured. Next step will be to remove it all and look for debris in the inlet air ducting.

This is not a slight rattle, it is substantial, which is lauder than the radio, maybe like a duct baffle rattling. But with the HVAC system off these should be only a little air flowing thru the ducts, not enough to cause such a racket. And it does not appear on every drive.

Air flow through the engine compartment is directed past the engine and down to the ground via the partition. So I may incorrectly discount it coming from the engine area.

Help appreciated.

2013 E84 i35 only 75k miles

[GML]

Resolution - Cause was the "Windshield Cover" that rubber trim piece around 3 sides of the winshield. It had released all across the top of the glass and was vibrating with the wind coming up over the car. The noise presented itself as coming thru the dash. Temporary fix was a 2" wide vinyl tape cover, replacement rubber on order.

[wheela]

Thanks for following with what the problem turned out to be, glad you got it resolved.