WillTravel, I already got the answer to this question on the call yesterday, as I've posted above: ... they specifically confirmed that this includes rentals through Hotwire and Priceline. In essence, they said, it doesn't matter whom I pay as long as the entire rental is charged to the card ... The CC company doesn't care if I pay a rental car company directly, or pay a 3rd-party who in turn pays the rental car company. I, the customer and cardholder, rented a car and paid *my provider* with my card, thereby fulfilling the requirement as specified in the cardholder agreement relative to payment: Initiate and pay for the entire rental agreement/contract (tax, gasoline,and airport fees are not considered rental charges) with your World MasterCard card. If a rental company promotion/discount of any kind is initially applied toward payment of the rental vehicle, at least one (1) day of rental must be billed to your World MasterCard card. Also note that: 1. Your car rental purchase confirmation document from Priceline carries your credit card number (last 4 digits); 2. The same credit card number (or digits) appears on the rental agreement you get when you pick up, since you give them this card as security. With these two official documents, it should be hard, zbenye thinks, for anyone to argue that the rental was not paid for with your card.