The 1920s were a heyday for rocketeers, who were attaching rockets to just about anything. Austrian space travel promoter Max Valier was pretty much the champ at this, creating everything from rocket-powered sleds and boats to rocket-propelled railroad cars and the first rocket airplane.
Work like Valier's led to real advancement in rocketry and public appreciation and support of space flight.
Then there were inventors like Daniel D. Hungerford and his brother Floyd S., of Elmira, NY. In 1929, they built their Solar & Interstellar Rocket Car, dubbed the "Shirley Lois Moon Girl" after Daniel's daughter.
Made largely of cardboard and linoleum, a 1921 Chevy chassis, and powered by a set of gasoline-burning rocket motors, the thing must have been a fearsome sight on the back roads of rural New York. The lightweight building materials were a safety consideration. "In case of trouble," Daniel said, "I wanted to be able to kick my way out." Amazingly enough, they got the thing registered and licensed in the State of New York.