I haven't thought about this in quite some
time, so thanks for bringing this up again.
For those who mentioned the chance of these
becoming trash made me think about a plastic
trash can.
Maybe find some that are thick enough,
and use the diameter curve to help with
the curved shape of the fender area.
And it will be deep/wide enough to extend
toward the center of the vehicle for better
coverage inboard? The molded in upper edge
might be left intact to act as a more reinforced
edge?
Cheap enough to play with and readily available.
Red neck engineering at it best? Or maybe worst?
Ha!