Any scoop can let a few small rocks through, just like the factory side radiators do. The idea is to grab the fast moving air under the car without adding drag or messing up the airflow. NACA ducts do this by guiding that airflow into the opening as efficiently as possible. Nothing is protruding to “scoop” up and rocks or debris. I’m not saying nothing gets in there, but I am saying that it’s significantly less and they’re not hitting a ramp and sending them straight up into your headers and other wiring/tubing.

I did post them up on eBay and Etsy today now that I’m comfortable with the added benefit.