Quick update. Have received the wheel arch liner from boutique-bordanova (the were very good and Google translate worked a treat!). Anyway, I bought the 'new' part. It's not genuine (never expected it to be) so I'll have to see how well it fits...but it's just a piece of plastic at the end of the day and as long a small it fills the hole I'll be happy..although the thought of putting a non-genuine part on on my car doesn't seem right!

My car never goes out in the wet anyway so it's not like I need it to keep the spray off! If it's rubbish I'll let you all know. (Just waiting for the screws etc. off Matt Brown to arrive now before I can fit it).