We took two cars and caravanned most the time. Decided to stop for lunch at some burger joint in Oregon. Sister-in-law was in the first car, and told the cashier she was paying for the car behind her too. The cashier looked at our order and said, "That's really nice of you, but you might want to choose a different order to pay for." I think the totals were something like $25 for her and $45 for us.