Referring to the holes throughout this bumper that’ll collect all that crap. Ask the jeep guys with their rocker sliders & steps that have holes. You should see the amount of crap that gets into places on my jeep.The factory Badlands bumper is made from metal so I guess it will rust off too?? Even the plastic covered ones have metal structures underneath.
I do live where they use tons of road salt. 1 big welded bumper sure would be easier to clean from behind than a metal one cobbled together from a bunch of smaller pieces.