I broke a few rocker panel clips on my '05 xk8. Couldn't find help in the forum. But managed to find a dealer that had the proper clips to attach the plastic cover to the rocker panel. From Harper Jaguar in Tennessee. The web site told me that the part recomended by other sites was wrong, it had the right parts, plus a diagram showing the clip and the plastic cover. Price was right too.

see: Part Number Part Name XR849718 Rocker Molding Clip $1.09