Math-U

Just finally tracked down a very agitating rattle/vibration on my 2015 GMC Sierra that seemed to be coming from my dash at highway speeds. Finally looked under the hood to see what air movement might cause to rattle. Eventually, I saw this cowl was cracked and weather worn right at the bottom of the windshield. The whole piece was kinda loose too. Anyway, I put some duct tape at the windshield/cowl interface to check and BAM! Sure enough, this is the culprit. Will order and replace asap. It's almost 10 years old so, I guess it was time!