Abstract: A sliding runner of a particular specified type and supporting a motor vehicle seat is provided with an anchor for the lower end of a safety belt for a passenger on the seat. The sliding runner is one having a lower generally channel section member attached to the vehicle floor and an upper generally inverted channel section member which interfits with the lower channel section member, the upper and lower members co-operating by way of ball races to facilitate movement of the upper member along the lower. The said upper member has secured thereto a jaw member which provides an anchorage for the lower end of a safety belt and which embraces the engaging portions of the said upper and lower members so as to be slidable with the said upper member while resisting disengagement from the sliding runner and hence providing a reliable anchorage for the safety belt.