I was playing around with an Alpine hood I had so Installed the NACA ducts (made them with 2 molds I made) and I mounted the scoop backwards to see it anything good happened to the airflow. My test was an epic fail. Up to about 40 the airflow did go in the desired direction. Above that I guess our windshields are too effective at stopping the air. I don’t have a cooling problem so I could not evaluate that.