had the same problem with the three hole type locking wheel nut ,one of the holes became elongated due to some nice tyre fitter over tightening them , tried various sources for advice for removal which icluded anything from semtex to grinding the bolt head off (without damaging the wheel?) in the end and in desperation went to my local VW dealer where they removed in approx. five mins by hammering an undersize socket over the bolt head and undoing and the best part they didn,t charge me not even for the socket they used and broke i assume.......wyn