[MattBianco]

I am not an engineer, but I play one at home. That area to which this thing mounts, close to the lower part of the windshield, has negative pressure relative to the highest pressure areas: front of the hood and top of the windshield. Those two areas have the highest pressure and any third party devices mounted there would slightly alter the pressure points against the skin/surface of the car and turbulence above the roof. This is why the front of the hood mounted bug shields you see on trucks achieve something. That something itself won't be a free lunch. They could well deflect the projectiles away from the hood and into the glass. I would also avoid due to reasons cited by others above.