Detroit killed six of its own car brands, and none of them made a car anyone else didn't

American carmakers spent the twentieth century building brand ladders. General Motors had Chevrolet at the bottom and Cadillac at the top with Pontiac, Oldsmobile and Buick between them; Ford had Mercury between Ford and Lincoln; Chrysler had Plymouth under Dodge. Each rung was supposed to catch a customer as their income rose, and for decades it did.

What hollowed the ladder out was badge engineering. To save development cost the middle brands stopped getting their own cars and started getting rebadged ones: a Mercury was a Ford with a different grille, a Plymouth was a Dodge, an Oldsmobile was a Buick. The saving was real and the cost was invisible for years — until the point of the middle brand had gone with it.

Saturn is the exception that proves it. Launched in 1990 as a separate company with its own plant, its own dealers and no-haggle pricing, it was folded back into GM's parts bin during the 2000s and lost the only thing that had made it Saturn.

The bill came in a decade. Plymouth ended in 2001, Oldsmobile in 2004 — the oldest surviving American marque, founded 1897. GM's 2009 bankruptcy took Pontiac, and Hummer and Saturn went with the restructuring; Ford closed Mercury in 2011. Retiring a brand is not free either: dealer franchises have to be bought out, and GM's cull ran through thousands of them.