A friend of mine was stopped on his way back from the Sturgis Rally. He was in a F-350, Ohio plates, pulling a 40' enclosed trailer with 9 of his friends motorcycles in it. They busted him for no DOT number, no logbook and hours, and equipment violations that are applicable to commercial vehicles only. BUT, he had a magnetic sign on his door that advertised his custom motorcycle business, and that (in the eyes of the officer) made him a commercial vehicle. Cost him $750 to get out of there.
Any signs on your truck or trailer?