We have not rented with Avis, but have had that issue with Budget. I get this awesome code/discount, show up there and they tell me, there is just no way they can give me a car at that price. Well, why was I able to reserve it in the first place? I was quite firm, I had a reservation and that needed to provide me with a car that fit my family and my luggage. It wasn't what I reserved, but it did fit us. Same thing happened at MCO. Tried to give me this really nice BMW SUV-upgrade from what I reserved, problem is, it wouldn't fit my luggage. We kept pressing, got what we needed. This year's rental should be interesting again, as we have a mini van reserved, through Budget, at a really good price.