When my truck (2020 F-150) was only two months old and with very low mileage, I hooked up my travel trailer and left on a trip. Once I returned I noticed that my tailpipe looked as though I had oil dripping out of it. It was soot mixing with water condensate from the exhaust. That's not the worst of it, I also noticed that the lower right quadrant of my trailer was spotted with the soot. It was very difficult to remove, acted as though the black soot was "melted" into the fiberglass of the trailer. Some say this is normal, maybe so, I'm not worried about the dirty tailpipe but the "damage" to my RV is another matter. Even after the scrubbing, some rubbing compound and waxing, if you look close you can still see some spots. Any thoughts, ideas, remedies or just "suck it up and put a metal shield on your RV to protect it."