[3] It was the first GM plant to build multiple car lines,[2] resulting from a Depression-spawned move to cut production costs by sharing components and manufacturing.

The originally Pontiac operated South Gate plant was part of GM's Southern California Division through 1942.

These "branch" plants built cars for distribution to a specific region, in South Gate's case the US West Coast.

This arrangement was short-lived, and GM returned the factory to building full-size Chevrolet, Oldsmobile, and Buick B-body vehicles for 1977.

Slow sales and efforts to reduce air quality issues resulted in plant closure, with production ending on March 23, 1982.