Looking at an old LaSalle this morning and its windshield, 1932
345B. The windshield is flat, one piece.
By the late 30s through the 40s we see split windshields and by 50 back to one piece.
What necessitated the advent of split windshields and then back to one piece. Was it a design element or a technical problem? Art
Split windshields dated back before 1930. Certain Fleetwood body styles had a split windshield, with each half independently opened. They were a product of styling, as well as a product of aerodynamics and manufacturing expedience. Rain water washes away from the center of a split windshield better than from a flat windshield. If one side of a two piece windshield is damaged, you need to replace only half ot it. If a half of a windshield is defective in manufacture, you dont lose the full expanse of glass to scrap. In the 1934 Chrysler Imperial Airflows, the one piece curved windshield debuted. The Airflow was an aerodynamic triumph, though a tragic failure in the market.
Curved laminated glass was no easy trick, but the glass makers were able to make curved windshields, beginning in 1948 (GMS "C" body), and in a couple of years, one piece corved windshields again. The "panoramic" windshields of the late fifties were a real breakthrough in manufacturing, and were more a styling thing than anything else. And to go a lurch further, Chrysler again startled the styling scene with compound curved windshields.