H. Repetition (Chapter 1-10)

"In the town, on the edges of the towns, in fields, in vacant lots, the used- car yards, the wreckers' yards, the garages with blazoned signs—Used Cars, Good Used Cars. Cheap transportation, three trailers. '27 Ford, clean. Checked cars,guaranteed cars. Free radio. Car with 100 gallons of gas free. Come in and look. Used cars." (61)

Steinbeck's repeated use of the word "car" almost makes it seem like there is no meaning to it - like the cars are not really cars anymore. It's called Semantic satiation. It happens when you say a word over and over again until it has no meaning to you. It just becomes meaningless sound.
And they aren't really cars. They're broken, filled with sawdust and have no working batteries. They're a pile of rusted metal, that's what they are. And they're sold for prices way above what they're really worth.
All these adjectives, "good", "cheap", "clean", used to falsely describe an object. Steinbeck uses these words sarcastically to describe the lengths of which the car dealers tried to reach to sell these incredibly worthless junk cars.