The word "车子" is formed by directly combining the character "车", which represents the core concept of a wheeled vehicle or car, with the character "子", which is appended to create a more colloquial, everyday term. This addition does not alter the fundamental meaning but imbues the word with a sense of familiarity and common usage, making it sound more natural and integrated into casual speech compared to the standalone "车". It is a straightforward morphological process where two characters are joined to produce a single, commonly understood noun.