I did just this past December, got a jeep through Thrifty. It was the best deal around by almost 50%, I looked at all options. When I arrived it was 1:30 A.M. Dec 26, Thrifty was out of all cars except mini vans. Evidently there had been a scheduling error, however this worked to my advantage. I got to return the car on empty free of charge and with my in laws we could all go somewhere in one vehicle. I was to cheap to rent the mini van originally as the Jeep was the best rate and the van was twice as much. The only issue was that the return is not at Orlando airport we had to take a shuttle back but it was quick and fairly painless. I would use the Southwest rental again if it was the cheapest. Side note, make sure to print your confirmation and have it in hand at the rental counter, there was a price error in Thrifty's computer and had I not had my confirmation I probably would have been in for a long argument.
MamaCatNV