Mud guard texture

[19sierra53]

This is the front mud guard on the rear tire on my truck. I washed it and noticed the texture on this face looks sandblasted or really rough compared to the one on the other side of the tire or the ones on the front tire. Does anyone else have this? I only have 5000miles on, i can't see it being from dirt/salt on roads. Also do all the trucks have the "rock guard" type spray on the fender/rocker in this area, or did the dealer do this?

[OnTheReel]

Mine are extra rough too, just as you describe. No clue why, and don’t remember how they were when new.

GM has painted the bottom of the trucks like that for quite awhile now. 

[19sierra53]

Ok weird. After washing i noticed the rock guarded trianglular area in front of the rear tire was on the grey side. I had to really buff to get it to go black, thats when i noticed the mud guard was real rough on that face only