Under-seat engines were becoming outdated in 1907, so Cadillac disguised the fact by mounting a dummy hood over the front axle on 1905 models, with a vertical radiator at the front. New single-cylinder models for 1906 were the K and M, which differed only in wheelbase (M was two inches longer). For 1907, the front fender contour was flattened, and a factory-installed Victoria top was offered, which added $100 to the $950 price.