Ooh, Subdivisions! GM had a lot of those in the 1920's & 1930's. LaSalle was a division of the Cadillac Motor Company, which itself was a division of General Motors. Marquette was a one-year(1930) division of Buick Motor Company, which itself is a division of GM. I believe Irving was a short-lived division of Oldsmobile Motor Company, which as we all know is a division of GM, and Pontiac was originally a division of the Oakland Motor Company, which superceeded Oakland in 1931.