The earlier term for a performance-modified car that evolved into “hot rod” was “gow job.”
In the early days of American performance-car culture, enthusiasts used “gow job” for a car altered to improve speed. The phrase referred broadly to mechanical modification rather than to one particular body style. Owners might tune an engine, remove weight, change gearing, or adapt parts from other vehicles.
The wording gradually gave way to “hot rod” during the early to late 1940s. The newer expression captured the idea of a car being “hotted up,” or made more powerful. The word “rod” has several proposed explanations: it may refer to a roadster, a popular lightweight starting point, or an engine component such as a connecting rod or camshaft.
The alternatives describe later or related styles, not the earlier general term. A “rat rod” is typically an intentionally rough-looking custom, a “lead sled” is a heavily customized low-slung car, and a “street rod” usually refers to a road-going hot rod built in a later tradition.