Here's some information and a pic of the plant entrance.
I'll see if I can find some more.
Cadillac Hamtramck Plant
2500 E. Grand Blvd, Detroit
The Cadillac Assembly Plant, also known as the GM Cadillac
Poletown Assembly Plant straddles the Detroit and Hamtramck
borders at Chene Avenue and I-94.
It sits on the former Dodge Main plant site,
which was closed in 1980 and demolished to make way for
Cadillac’s Detroit-Hamtramck Assembly Center.
Much of Detroit’s Polish neighborhood,
called Poletown, was cleared for this project.
A very contentious legal battle over the condemnation proceedings
went all the way to the Michigan Supreme Court.
The facility now produces Cadillac DeVille and Seville vehicles.
This plant is one of GM’s newest and most automated plants. http://www.autofieldguide.com/articles/110103.html