The excellent response to RKO Radio's The Girl from Mexico prompted the studio to fashion an entire series based on the misadventures of fiery Latin American entertainer Carmelita (Lupe Velez). The series proper began with 1939's Mexican Spitfire, in which the recent marriage between Carmelita and stuffy-but-likeable American businessman Dennis (Donald Woods) is threatened by the interference of Dennis' wealthy, snobbish Aunt Della (Elizabeth Risdon). Fortunately, Carmelita finds an ally in the form of Dennis' easygoing Uncle Matt (Leon Errol). The plot hinges on an important business deal between Dennis and the veddy British Lord Epping, top man of a major whiskey firm. Luck of luck, Lord Epping is an exact double for Uncle Matt, leading to a series of gut-busting complications. Somehow it seems logical that Mexican Spitfire should end with a Keystone-style pie fight.