Might be worth checking into, Garry.
Back when I competed heavily in the NSCA and traveled to big shoots I saw many decked out UTVs and trucks and trailers with a magnetic sign on the door or tailgate indicating the name of a personal business. I asked about the prevalence of this and was told that by simply doing so the shooters could write off every cent of the weekend's expenses as business expense . . . . mileage, hotels, meals, shells, entry fees, etc.