The auto industry took a big step forward in 1935 when General Motors and Fisher Body introduced the one-piece steel roof panel.

Well into the 1930s, American car bodies featured a strange anachronism that dated back to the horse-and-buggy era. Partly due to tradition, partly due to the limits of steelmaking at the time, cars did not have metal roof panels. Instead, the major portion of the roof was filled with a piece known as a top insert, a rickety assembly of hardwood, wire mesh, fabric, seals, and paint that leaked, squeaked, was time-consuming to manufacture, and added little to the structural integrity of the body shell. As car bodies became more sleek and modern every year, the old wood-and-fabric top insert was a curious throwback.

The opportunity for change arrived in 1932, when Inland Steel of East Chicago, Indiana, installed its first 76-inch wide rolling mill. Finally, sheet metal was available in sufficient width and quantity to produce roof stampings in one piece. But first the entire body industry would require readjustment, too: larger, more powerful stamping presses, bigger trucks and railcars to handle the materials. For the 1935 model year, General Motors and its Fisher Body division were able to offer the innovation on Pontiac, Oldsmobile, and Chevrolet Master models. Aggressively marketed as the Turret Top, GM’s all-steel roof was quieter, tighter, far stronger — and ultimately, faster and cheaper to make than the old wood-composite construction. Naturally, the rest of the automakers followed along as soon as they could.

https://www.macsmotorcitygarage.com/1935-gm-introduces-the-all-steel-top...

In 1943 or so, they'll be digging the old Nash out,
just to salvage those tires.

He's in the car.

Circa 1925 Nash.