Buick did it in 1953. Depending on what model you had, it was either 6-volt or 12-volt. The Specials (like mine) were 6-volt, but the fancier models like the Supers and Roadmasters (the V8 models) were 12-volt. '53 is also the year Buick came out with the Nailhead, so that might explain the switch.