I made this after a failed attempt at using window film. When the weather cooled that stuff just shattered.
I didn't have enough coroplast to make the whole thing so made in two halves. Elections in town this month so I'll make another.
ha ha!
This one I screwed directly into the plastic of the upper grille. Will use stainless here too. No perforations after 2 years. I think that's just because it's higher up and less prone to road grit spray on the highway.