Tube probably bent when Installed too. Because I bought this slider before I go to offroad with this vehicle and I noticed after installed.The rust is the least concern I have is these photos, first thing I noticed was in the first photo where the rust hole is it looks like your tub is bent in wards with some paint chipping off on the body. Could be the reason you got the sliders but it does look like paint is chipping. Second those holes are way too big for the hardware, those washers are going to rip out.
Remove each bolt one at a time, apply some paint with a small brush or toothpick, reinstall bolt with larger putter diameter washer, mover the the next one.
Those washers are too small or the holes are far too big. Water is collecting there and sitting. When installing those, they should have put a dab of RTV over the nutserts as well as the washer to make a nice seal. Seems like it's nothing more than a sloppy install. I'd take em off, get them line-xed, and bolt them back up again, with slightly larger washers, and RTV
Those washers are too small or the holes are far too big. Water is collecting there and sitting. When installing those, they should have put a dab of RTV over the nutserts as well as the washer to make a nice seal. Seems like it's nothing more than a sloppy install. I'd take em off, get them line-xed, and bolt them back up again, with slightly larger washers, and RTV