Those large side pieces are for channeling air into the radiator area for more efficient cooling and appear to be made from plastic, not metal. My guess on the circular recess is something to do with wind noise reduction. They would be smooth, otherwise.
The radiator support is not shown in that picture.
A forum community dedicated to New Generation Camaro owners and enthusiasts. Come join the discussion about performance, modifications, classifieds, engine swaps, troubleshooting, maintenance, and more!