It depends on the situation. In case if your rental car is reserved by other customer, you can’t extend your rent of booked cars. However, you may exchange your rental car by any other available models. If you are exchanging within same range and category, rental charges will remain same. If you are exchanging within lower and higher range, rental rates will be adjusted accordingly. In case if same rental car will not be reserved, then you may extent rent by contacting our customer care representative or sales department.