You can enforce that in a building but it's impossible to enforce it in a truck. Unless someone wants to follow the truck with his car that's something that cannot be enforced. It is up to the man driving the truck to decide on what kind of enviornment he will spend the day in. If the guy using it before you wants to leave his mess behind, then it's up to you to either do something about it or sit in it. I would never go to a boss to complain either. That's not me. I'll do what I have to do to make my day tolerable.