The invention relates to a sliding door (1), especially for a motor vehicle, comprising a prefabricated system unit (3) provided with a number of functional modules. A sliding door drive (7) is arranged on the system unit (3) as a functional module, said drive comprising a drive motor (9) and a coupling element (14) driven by the drive motor (9), said coupling element forming a separable coupling with an external displacement mechanism (18). The extensive prefabrication enables the assembly of one such sliding door (1) to be significantly simplified.
