I found the plastic from cheap dollar-store trash cans and the like is RELATIVELY easy to cut (I didn't say it was easy, just relatively) with some heavy-duty scissors (like Titanium models lol) and make for excellent grill cover pieces.
The plastic is sturdy enough, but easy to drill through etc, etc...
The worst part is sometimes it's not big enough pieces, but if one side of a plastic 'square like' trash can is big enough then the other side can make a 2nd piece the same size (excellent for those 'split' grilles).
The worst is color, most are white, just looks kinda ugly or trashy (no pun int)...
One could paint red or black, maybe grey.
A FE gauge should be standard equipment in every vehicle.