We had booked an intermediate (Dodge Avenger or similar) for our three week vacation. When we wanted to claim the car at the JFK airpot location, we were told that the the only intermediate left was a Beetle. If we wanted a car that was big enough for the four of us (two adults, two small kids), we had to pay for an upgrade to the next category.

Only after a long argument and after pointing the representative to the description of the category that stated that the car would seat five and have space for three pieces of luggage, another intermediate was "just checked in". We received a Chevy Cruze which was fine for our purposes. The lot looked full, BTW.

Has this happened to anyone else? Is there really a risk that the size of the car is completely unrelated to the category booked?

Yes. As of a few years ago, cars are now classed based on their acquisition cost, not necessarily their size, aka class creep. The Beetle has long been a midsize with Enterprise/National, and the Avenger/200 twins have recently been creeped up to fullsize.

Good to know. It of course creates a risk and makes planning difficult when you don't know what size of car you will receives. In our case everything worked out, but there is no way we would have fit four people and the luggage into a Beetle.

The rate description does mention the number of people and amount of luggage that can fit into a a car of a particular category http://www.budget.com/budgetWeb/html...rs/medium.html, but I guess this is nothing one can rely on.