But for a few years before the war, things were different for Oldsmobile. This mostly had to do with grilles, which featured complicated patterns of bars and other details. I will leave it to any readers with deep knowledge of prewar / postwar GM styling studio personnel and practices to provide details as to how and why this change happened. For now, I'll guess that a change of head designer probably was an important factor, though styling supremo Harley Earl exercised close control, and the change of emphasis must have had his approval.
America's entry into World War 2 in December, 1941 led to the early 1942 curtailment of car production "for the duration." As a result, not many 1942 models of any brand were built. When production resumed for the 1946 model year, the era of clean Oldsmobile styling began.