Guessing later C3's will be different to earlier ones like mine - but if we're talking about the small stainless/body coloured pieces that sit where the fenders 'touch' the windscreen.......I think Gavin has just posted the info you need........TBH historically and in addition with with items like older door cards that won't sit in place and delicate age degraded front grille plastic, and loose trim bits gone to the local auto paint shop/auto factors........and bought a tube Sikaflex body adhesive/sealant and 'tacked' the item down with some of this. Great stuff IMHO - available in limited colours - it has a high adhesion rate and it can be moulded too.