You say its UK spec but if someone changed the light for Euro right-hand driving then for the UK you will need to change it back to LH driving. Its possible that no one ever changed it - we never bother with adaptors when we go to France/Spain for a couple of weeks each year.... You can check the part numbers - look up online (Fowlers website for example) and see if you already have the UK one fitted and if so you've nothing to worry about...........