A restraining strap system for a child car seat (3) in a vehicle. The child car seat (3) is of a type which can either be rearward or forward facing. The restraining strap system includes a restraining strap (6) having latches (9) at both end thereof which engage with latching bars on the vehicle. The restraining strap (6) passes through separate strap passages (7, 25) for each of the rearward and facing positions of the seat. A retention strap (13) is mounted to the child car seat at one of its ends and to the restraining strap (6) at the other end thereof to prevent complete removal of the restraining strap from the seat when moving the restraining strap from the rearward facing strap passage (25) to forward facing strap passage (7) or vice versa.