I made a backup reservation with National...in case at check-out the agent decides to reprice the reservation, they can just walk away and get the other car.

The concern I have is a reprice when the car is returned or the contract is audited later on - if they have a printed reservation with total 'x', can the location or Avis arbitrarily change the price after the fact due to a website error? I should think their window for a reprice exists only when the car is checked out, not at return or weeks later.

I went back to avis.com to try and rebook the reservation, but the site is still down....amazed at the level of incompetence within their IT department.