* Definition of "car" is fluid: Throughout history, the definition of an automobile has changed. Early vehicles might be considered cars by some but not others.
* Records are incomplete: Production records, especially for very small manufacturers or early automotive ventures, are often lost or incomplete.
* "Made" is ambiguous: Do we mean total production ever, or the lowest production number of a specific model in a single year?
To find a contender for a low production number, you'd have to look at very obscure, hand-built vehicles from the early days of the automobile or extremely limited-edition supercars of modern times. There's no central registry keeping track of all such vehicles.
