inner liner drw question

hi folks, last day I was driving in very crappy roads, full of very thick mud ( I work in the oilfield industry and roads are intended to last a couple of weeks)
so when I was driving I heard a noise like stones at the back, when I look at the mirror I noticed that the inner mud cover was left behind, went to pick it up, but I might have lost the other one somewhere...anyway the one taht was left was in good condition.
my question is do you have any upgrade for these or any idea, i was thinking about designing two with a thin metal sheet but then it could be too much noise with stones hitting it?

any idea? i want to avoid the snow and mud getting at the front and back of the rear wheel

thanks:thup: