The first Cadillac model produced was the Runabout & Tonneau. Introduced in 1903, the first Runabout & Tonneau car produced was the Model A. Through the production of the Runabout & Tonneau, a number of variants were produced that varied slighty in wheelbase and panelling. These variants included the Model B, Model D, Model K, Model M, and Model S, which were offered with single cylinder or four cylinder engines. Production of the Cadillac Runabout & Tonneau lasted until 1908.