I don't get much airflow through the vent, but I didn't expect to. My knowledge of fluid dynamics (us wonderful engineers!) knew that, in certain conditions, it's just enough airflow to break up the low pressure "bubble" behind the fairing a quell buffeting of the high speed air going over the windshield. This was the #1 reason why I went with a Clearview in the 1st place, having tried various other brands & heights that just didn't work for me.