Detroit/Hamtramck Assembly

Detroit/Hamtramck Assembly, also referred to as Factory Zero (and historically as GM Poletown), is an automotive assembly plant located on the border between Detroit and Hamtramck, Michigan, United States, owned and operated by General Motors. It currently assembles the GMC Hummer EV, Cadillac Escalade IQ, Chevrolet Silverado EV and GMC Sierra EV battery electric vehicles for the North American market.

The site was originally a factory for Dodge, known alternately as Dodge Main or simply the Dodge Factory. It opened in 1911 and operated continually until the 1970s when diminishing demand led to the site increasingly being used for secondary roles. In 1979 it was announced it would be closed, which occurred early in 1980. The site was dormant until 1981, when GM purchased it for $1 with plans for a large factory complex covering the original Dodge site and a number of surrounding parcels of land. These included Detroit's Poletown neighbourhood, which had been a location for immigration from Poland and other countries. Attempts to stop these neighbourhoods from being demolished led to several court cases, which GM won.

The new plant replaced GM's Detroit Assembly, which had been the primary facility for all Cadillacs starting in 1921. The new factory officially produced its first vehicle on 4 February 1985, a Cadillac Eldorado. Over the next 35 years it built vehicles for GM's Chevrolet, GMC and Cadillac divisions, originally known as "BOC" for Buick/Oldsmobile/Cadillac, but two of those nameplates have since been discontinued. In early 2017 it had approximately 1,800 hourly and salaried employees, and 924 in late 2022. Since opening in 1985, more than 4 million vehicles have been built at the plant.

As of May 2020, the plant is being retooled to produce electric vehicles, and took the name Factory Zero as part of this rebuilding. The first vehicle rolled off the new line on 17 December 2021, a GMC Hummer EV.