Seat of an automobile

The seat (1) has an elastic return connection (7) connected to sides of a fixed rail and a movable rail (5). The connection is mounted to exert return effort when a backrest (3) is in retracted configuration. An end (8) of the connection is connected to the rails via a re-adjusting device (9). The end is immobilized by a bolt (10). An unlocking unit (11) unlocks the bolt temporarily, and is activated by setting the backrest in an access configuration to a rear seat so as to release a clearance of the end moving forwardly against the device.