20th Century-Fox came into being in 1935 and those cars are circa mid 1930s, so I’d say this billboard probably came up not long after 20th Century-Fox was born when Life magazine took this photo. If you look under the logo, you’ll see “Hollywood Studio” which suggests that the company name wasn’t too familiar to people. In case there was any doubt, Darryl F. Zanuck figured he needed to tell people what “the world’s standard of entertainment excellence” actually was.