The driver charged another 15 USD depite the prepaid voucher. He could not explain why but he told us that he have to collect the amount in advance so we were forced to pay. Sounds like blackmail to me.
The same review applies to all four of our transfers with carmel limousines.
Hard to know what to say except that it did exactly what it says on the tin--a private transfer for 4 people and luggage from a downtown hotel to Dulles Airport by Cadillac SUV. Arrived exactly on time, vehicle clean and comfortable, driver helpful and friendly--what more could you ask for? Granted it probably cost a lot more than a cab, but I got what we wanted.