The Opel 4 PS, popularly known as the Laubfrosch (treefrog), is a small two-seater car introduced by the auto maker Opel early in 1924. Subsequently, various...

first mass-manufactured car, the Opel 4PS Laubfrosch (Tree Frog), came off the line at Rüsselsheim in 1924, soon making Opel the top car builder in Germany...