I guess it's possible it could be manufacturer defect. This was the first time I waxed it wand was up close checking everything out. I just know that when it was wrapped in plastic, it left all kinds of marks on the RV from the plastic sticking to the fiberglass. I guess I assumed this was from that as well. I will say that the two main spots I notice it are in the same spot on either side of the RV. Both near the front cap on either side, pretty much in the exact same area. I doubt I could prove it was a manufacturer issue and get it covered under warranty though....might be worth a shot.