The first use of tinted glass for Chevrolet was in passenger cars in 1952. Trucks followed a year or two later.
The door glass in the 1940 truck was safety sheet. The windshield had safety plate. The cars used the plate in all windows. The sheet could tend to be a little "wavy".
The glass used in todays vehicles if of the Tempered type. Its more or less moulded and if chipped or broken in falls in a million small pieces,
The 1940 type of Safety glass was laminated. That is two thin shees of glass with a plastic sheet in between. That is still available today for replacement
