Managed to find a hole in the body near the bottom of the sill end cap which I used for mounting a bracket so the bottom of the flap could be bolted on better then covered the flat face of the end cap with PVC tape before using PU sealant to bond the mudflap in place. The PVC tape means I can always peel it off in the future as the PU would be a nightmare to remove.Did you go for Velcro to avoid having to drill the sill? I've got a set of Kaylan flaps for my RS and should really get around to fitting them sometime