U.S. car designer who worked as an engraver before joining Brewster and Co., coachbuilders in 1913, where he was sponsored in study at the Andrew F. Johnson Technical School in Manhattan to learn body design and advanced drafting, graduating in 1917. He then went to Chevrolet as assistant body engineer, but rejoined Brewster in 1918. At Brewster, each designer was called a "master craftsman," and had his own staff of assistants and apprentices who roughed out the work, but final finishing was done by the master craftsman in a closed room to conceal secret techniques. In 1920 Dietrich and Thomas L. Hibbard left Brewster to open their own firm, Le Baron Carrossiers, in Manhattan, and initiated the process of designing an entire car in detail on paper so as to achieve a harmonious and unified appearance (previously, coachbuilders designed piecemeal as they received separate components from the manufacturer). Le Baron provided clients with 1/12-scale pen and ink side views and color renderings for paint schemes. These pioneering techniques would later become standard tools for industrial designers. In 1924 LeBaron Carrossiers merged with the Bridgeport Body Company to form LeBaron Inc., in order to design and produce bodies designed by Dietrich. In 1925 Dietrich sold his stake in LeBaron, Inc. and joined Murray Corporation of America, the Detroit company that built most of Lincoln's and many of Ford's production bodies. Murray and Dietrich shared ownership of a subsidiary manufacturing plant called Dietrich, Inc. The move by Lincoln to engage custom body builders on its standard production designs initiated a trend for all car companies to do the same. Dietrich assisted Amos Northup in the design of the 1931 Reo Royale Eight, which became a sensation because its front fenders joined in a "Vee" like the wings of a bird in flight. However, Dietrich was forced out of Murray in 1931. In 1932 Chrysler established an Art and Color Department of five, led by industrial designer Herbert V. Henderson. Dietrich was hired as a consultant, and served as unofficial head of the Department. Previously, Chrysler had relied on the Briggs Manufacturing Company, its major body supplier, for styling. In 1934, after the Chrysler Airflow, designed by its engineers, failed in the market, Dietrich designed a more conventional grille for a companion model, the Airstream, which was more successful. Dietrich soon became official head of the department and assumed responsibility for exterior design. But engineers were not collaborative, and he was ineffective, so he left in 1940. He then founded Ray Dietrich Inc. in 1949, worked for Checker Cab starting in 1953, and for Lincoln and Mercury until his retirement to Albuquerque in 1969.