A childrens book by John Sheridan.
Wild cars live in the desert munching on oil lumps that are found there. They resemble modern automobiles except that they are driverless and furry. Eric is the largest car, and is expelled from the herd because he eats too many oil lumps.
He wanders off until he comes to a scrapyard where an inventor lives, and punctures one of his tires on a rusty nail. The inventor patches his tire, they become friends, and Eric gives the inventor rides to the cities of A and B.
A and B are two large cities with skyscrapers in the shape of their respective letters.
Soon the inhabitants of A and B decide that they want cars too, so they go into the desert round up wild cars and break them in rodeo style.
Before long they have built a vast network of motorways and spaghetti junctions between A and B. The noise and vibrations from all the cars causes A and B to crumble. The inventor decides enough is enough, and hits on a solution. A howdah (like the kind used for elephants) is placed on Eric's back, and he volunteers himself as public transport. The other cars are set free.