Random auto thought
Why did it take 50 years to extend the body beyond the wheels?
From 1890 to 1947 all passenger cars had separate fenders for all four wheels, and the envelope for passengers was strictly inside the wheels.
In '47 Crosley
and Kaiser merged the fenders to make just one fender per side, but the inner body was still inside the wheels. The roof and windows didn't stretch out horizontally until the 1960 Valiant.
There were always examples of full-width envelopes. Streetcars and railcars went WAY out beyond the wheels in both directions. Railroads have the same wheel-to-wheel width as autos, but the typical railcar is 10 feet wide.
Box vans always enclosed the rear wheels entirely, with insets for the rear wheels when needed.
Since the idea and example were available BEFORE cars had motors, there's no logical reason for the delay.