Last month our group of 5 decided to ask for a mini-van instead of the 2 cars we had reserved for our original group of 6 persons, but one didn't go.

Since I was Avis Preferred, I got the privilege of asking. At the Preferred counter, the agent called her supervisor (?) saying that an Avis Select (I didn't know that!) needed a mini-van for a day and was willing to pay the extra rental amount.

Well, I didn't pay attention to the charged amount until after coming back home and it turned out I was only charged the rental fee for the originally reserved car.