They do come FOC with the Q5. It has a feature on it where it recognises that there are roof bars fitted, it then makes small changes to the ESP program assuming there is weight on the roof. Thats why the one location point has three holes in the roof rail as this is where a hall effect switch is located in the roof rail detects a magnet in the roof bar.
They are always coming up for sale on Fleabay, I bought some and modified them to fit my A4 Avant.
Karl.