Seat belt device for a rear seat assembly of a vehicle

The device has a belt guide part deflecting a safety belt (7) to a belt winder (11). The belt guide part is mounted together with the belt retractor in a region of a rear-side hold to a vehicle shell. The belt guide part and a holder (25) for a wetting running wall cassette (23) are mounted together to form a common structural unit, which is mounted on a common connection of the vehicle body shell. The belt guide part is mounted on a reinforcing profile of the vehicle body shell by interposition of the holder that is supported by a fuse element in a base body of the guide part.