I have the same problem. Before taking my car for a service & mot this week, I checked and no locking wheel key, it is always in my car. Then I remembered my partner took it to have brake pads and discs replaced last year at Halfords and I suspect they didn't replace it and on collection my partner didn't check. I am hoping they have a box somewhere where they save left ones. I do feel it is the garages responsibility to replace it where they found it when they have finished. Typically I didn't check until 6 months later! The mechanic who completed the service explained that he was unable to remove them with a hammer and socket because the outer bit of the nut spinned, so that doesn't appear an option for me. Fingers crossed Halfords still have it as I don't think I have the code and need a new clutch :(
