The medieval and early modern social system was based on ideas of people being born into a certain social class and achieving maximum happiness by accepting the privileges and duties of their station.
Being content with your station is, of course, antithetical to the American class system, which presents itself, with some justification, as a meritocracy.
The optimistic age of fins and chrome of the late '50s and early '60s gave way to the practical station wagons and Japanese imports of the 1970s, a time when both new suburban middle class and a recession made it necessary to simultaneously drive longer distances and conserve.