Yeah my box came with the claw things but they're not perfect. They're apparently not designed for wingbars - whispbars prob the same. They only work properly on square or aero bars. Also, they take up boatloads of room inside the box. Instead I swapped them out for the rail kit. A little more fiddly, but much more secure and takes up zero room in the box. It's essentially a t-piece screw that slides onto the bar then a nut on the inside of the box.
MY14 Space Grey F11 530d M-Sport