Don't park in the driveway, park on the street
If you go to a signing, it is rude and could cause a nuissance to park in someone's driveway. Someone might want to get out who you might be blocking, or someone might want to come in. Simply park on the street. If its not safe or easy to park on the street, call and ask permission to park in their driveway. If their driveway is 200 feet long, then you have no choice but to park in the driveway. If there is six feet of snow piled up, you may have to park in the driveway. But, in normal suburban situations, its best to park on the street so you don't block someone or have any oil or fluids from your car drip onto the borrower's driveway.