Here's Fussell's take.
The automobile, like the all-important domestic façade, is another mechanism for outdoor class display. Or class lack of display we'd have to say, if we focus on the usages of the upper class, who, on the principle of archaism, affect to regard the automobile as very nouveau and underplay it consistently. Class understatement describes the technique: if your money and freedom and carelessness of censure allow you to buy any kind of car, you provide yourself with the meanest and most common to indicate that you're not taking seriously so easily purchasable and thus vulgar a class totem. You have a Chevy, Ford, Plymouth, or Dodge, and in the least interesting style and color. It may be clean, although slightly dirty is best. But it should be boring. The next best thing is to have a "good" car, like a Jaguar or BMW, but to be sure it's old and beat-up. You may not have a Rolls, a Cadillac, or a Mercedes. Especially a Mercedes, a car, Joseph Epstein reports in The American Scholar (Winter 1981-82), which the intelligent young in West Germany regard, quite correctly, as "a sign of vulgarity, a car of the kind owned by Beverly Hills dentists or African cabinet ministers."