Send them this way.
Seriously though, those grey clips are not exactly weak (which many of us have experienced changing side skirts, arches and the like), but for some reason the 2nd gen has a way (a knack, you might say), of knocking them off.
With mine (and the press car), it actually appears from the markings in the dirt, and "fold" of the soft wheel arch liner, that the tyre somehow manages to come into contact. I would guess with the weight of the front end, and the rotation of the (sticky) rubber tyre, even very strong clips might struggle to hold on.