A fixed length of belt has an outboard end attached to the door and an inboard end attached to the vehicle body forwardly of the seat. A track extends longitudinally inboard the seat and mounts a belt carriage which slidably receives the belt intermediate the inboard and outboard ends. Opening movement of the door causes the outboard end of the belt to be moved outwardly and forwardly so that sliding movement of the belt through the belt carriage causes forward movement of the belt carriage to stow the belt forwardly of the seat. A spring retracts the carriage toward the seat to establish the belt in a rearward restraining position when the door is closed. In the preferred embodiment, the belt having its inboard end mounted on the vehicle body forwardly of the seat has its outboard end attached high on the vehicle door to provide a diagonal shoulder belt. A lap belt has an outboard end attached low on the vehicle door and an inboard end mounted inboard the seat. A retractor is associated with at least one end of the lap belt to extend the length of the lap belt during door opening movement. The lap belt is slidably received by the belt carriage so that forward movement of the carriage by the shoulder belt during door opening movement also unwinds lap belt from the retractor and moves the inboard portion of the lap belt to a stowed position forwardly of the occupant.