The foam parts are laid flat on the roof of the vehicle, then the front strap goes through the 2 open doors, passing behind the heads of the driver and front-seat passenger. Repeat for the rear strap. Repeat for the rear strap. Bring the strap through the buckle, tighten, then attach the boards to the roof with the remaining length of strap. Do not run the straps through your vehicle’s open windows with the doors closed – you will not be able to open the doors. Do not overload boards. Regularly check that the straps are tight enough. Respect regulations regarding items carried on roof racks.