In one magazine article that appeared in 1949, it is called the "Vicinity Car" . . . but after researching what little other Airway material is on the web, it doesn't seem that anyone other than the magazine article author called it that. Could be, though. You're right, they did make two (which I didn't know), a coupe and a sedan. Although the puzzle car looks like a coupe, one article (using the same photo you did) calls this one the sedan. Do you have a photo of the coupe? I just wonder how they differ.
Here's one of the few actual ads to appear for the car:
600 pounds - 600 bucks . . . such a deal!