Detroit

General Motors' Detroit-Hamtramck assembly hall—D-Ham to its friends—is a Dickensian old shed of a car factory where, for years, GM has knocked together some of its most unloved automobiles. No robotic skillets or rotisserie carriers cradle the cars on their way through the factory, no video monitors at the build stations. Compared with some of Europe's sun-flooded auto ateliers, D-Ham looks less industrial than correctional.

The...