An exception was the 1934 Chrysler CW Custom Imperial Airflow that had a slightly curved windshield. This was the top-of-the-line Airflow where prices were high and sales volumes quite low, compensating for likely high manufacturing breakage rates for the curved glass.
By the late 1930s glass forming technology reached the stage where slightly curved backlight glass could be made economically. At that point, Cadillac retained the three-segment motif on some of its models as a prestige marker. For 1950, senior General Motors brands were given wraparound backlights, but technology intervened again. The entire window could not be formed, so three segments had to be used. This problem was resolved for 1953 model.
These various points are illustrated in the images below.