How do I fit the wind deflector?
Using 4x slide nuts of the M6 size, you slide them into the front rail from the underside. Affix the wind deflector in such a way that the angular side is at the front of the roof rack. When looking at the front of the vehicle it should deflect air and water toward the roof (not scoop it.) You will have to use 4x m6x25mm button head screws and an alen key to tighten.
NOTE: it is far easier to do this when not fitted to the vehicle and while the rack is upside down being assembled.