As you posted this in August i'm guessing you've sorted this but i'll post to maybe help others! Halfords used to sell a locking wheelnut removal tool for a tenner...i don't think they do now but some still may have stock and it might be the sort of thing a small motor factors shop may have in stock.
I was suprised when i saw them in halfords as they were next to their locking wheelnut sets! Kinda daft having locking wheel nuts when they sell a tool that removes them as easy as a spanner on a normal wheelnut!?!
Mark
