Hmmm. Speakers next to a vent?? Not sure Id do that. My truck flows regardless if I have the selector on or off. Defrost for your side windows I guess. Id prob raise them about 4 inches min. Be closer to the ear level, Thats me, Still looks badazz though. Sound to the user is all that mattersLooks decent in the car. The A-Pillar is held in by a tab at the bottom and three press in plastic fasteners. I took some fast hard corners and she stayed in place. I am happy.