 Owners included Jack L. Warner of Warner Brothers film studios.With the outbreak of World War II in 1939, the proposed further boring-out of the engine to for a 580K was aborted, probably after only one such car was made.Chassis production ceased in 1940, with the final 2 being completed that year, and earlier chassis were still being bodied at a steady rate during 1940, with smaller numbers being completed in the 1941–1943 period.