Our truck has this as well. Also, we have even noticed this on quite a few 2nd gens when installing steps as well. I think white contrasts the most so its even more obvious.
its the rubberized rock guard that they spray on the bottom of the rocker panels that then gets painted over.Well, I hate to be the one to point it out but if you find something on a vehicle you’re looking to buy that’s unacceptable to you then don’t buy it. Simple.
It is the first vehicle that I have seen it this bad on though. The paint looks smooth with no runs anywhere so I do think it’s undercoating or galvanizing.