The Popsnorkle family decides that the old family car is ready to give up the ghost. The whole family, Mr. Popsnorkle, Mrs. Popsnorkle,. and the five little Popsnorkles head down to the car dealerships to look at new cars. They fall in love with the Tooth-Gnasher Superflash and discover on the test drive that it can turn into a dinosaur, an elephant, a turtle, and a chicken, much to the dismay of the car salesman, Mr. Sandy. They trade in the old car and give Mr. Sandy a lot of money and drive away in their new car.
Tooth-Gnasher Superflash is about as close as you can get to an actual standalone Daniel Pinkwater book. The story is fun and fastmoving. About the only connection is the wonderful recurring Chicken Theme. Many readers know about DP's own automotive history, and his occasional calls into Car Talk. I think buried somewhere on the Car Talk site you might still be able to find a photo of DP and one of the dogs riding in the BWM he bought used.
Mr. Popsnorkle looks a little bit like DP himself, to me. Mrs. Popsnorkle has the look that seems to be so common to mothers in Pinkwater books. The five little Popsnorkles, with their rainbow colored clothes and lack of appendages are the opposite of what we usually see in Pinkwater. Most of the other books have children as the central characters and the adults as incidentals who spout stock lines. In this way, Tooth-Gnasher Superflash really is an exception.