Hot rod cars

Hot rods are typically American cars with large engines modified for linear speed. The origin of the term "hot rod" is unclear. One explanation is that the term is a contraction of "hot roadster," meaning a roadster that was modified for speed.
 

The term seems first to have appeared in the late 1930s in southern California, where people would race their modified cars on the vast, empty dry lake beds northeast of Los Angeles under the rules of the Southern California Timing Association (SCTA). The activity increased in popularity after World War II, particularly in California because many returning soldiers had been given technical training in the service. Many were prepared by Bootleggers in response to Prohibition to enable them to avoid revenue agents ("Revenooers"); some police vehicles were also modified in response.