Don't use Auto Europe, they are a scam! They only have phone number to the UK using UK business hours and no email address. They will ask you to prepay your reservation and if you are 2 hours late (say your flight is delayed) they will not honor your reservation of provide you with a refund. Also the big car rental companies don't like using them, so they will be less helpful to you as a customer. Book directly with Avis, Enterprise, etc.