The car rental business, like the airline business and the hotel business, is characterized by companies trying to sell/rent a perishable commodity in the midst of overcapacity and pricing often below cost. As a result, any time you change anything, the provider wants to sock it to you, the customer. When you move your flight a day earlier, they charge you a fee even if they have space available a day earlier. When you extend your stay at a hotel for one day, they try to charge you rack rate because of the “high occupancy”. Although it seems logical to say, “Just leave the car in the lot for the third day”, the fact is you have changed your plans and they are going to try to make you pay more for that. It is a sad fact of these kinds of businesses.