Concerning those two photos of assembly plants, they were taken in 1980, in Detroit, while on vacation. The one picture with cars stopped at an intersection (rush hour) shows the Wyoming (Export) Plant on the left and the McGraw (Glass) Plant on the right. If you look closely you can see the overhead walkway between the two plants. The McGraw plant was built in 1937 and initially was a stamping plant for the DeSoto Assembly (Wyoming) plant .
The second photo is the west side of the Wyoming Plant. I pulled off the road and pointed the camera south, looking back at the intersection taken in the first photo. The Wyoming plant was built around 1912 by the Saxon Motor Co., a company started up by a gentleman named Hugh Chalmers and his associates. During WW I the plant built war materiel. After the war Saxon sales collapsed and GM bought the plant. Either GM assembled Buick cars there or they prepared Buicks for export until the Depression hit.
Chrysler purchased the plant in 1934, and in 1936 updated the plant to begin assembling DeSotos for the 1937 model year.
Somewhere I have an aerial photo of the Wyoming plant, taken in the early 1940's. Someone wrote on the back of the photo, "photo of auto assembly plant, DeSoto County, in Wyoming." Had things a little mixed up.
There was a third DeSoto plant, on West Warren Avenue, only five minutes away from the Wyoming/ McGraw plants . This plant was acquired in 1948 by Chrysler from Graham-Paige Motors. DeSoto bodies were built there from 1950 to 1958 and DeSoto hemi V8 engines 1952-1958. DeSoto production was moved to East Jefferson for 1959, and Imperials were built at the West Warren plant for model years 1959, 1960 and 1961.