Are these the type where the outer turns free and can be removed by the key?
If so, removing them can be difficult.
I did hear of some locking wheel nuts like these that could be removed by
whacking the head with a hammer. The lock innards shattered and the outer
collar could be removed. Once you are at the actual bolt, removal becomes
easier.
How about joining a rescue organisation and managing to have a flat. The
mechanic they send to help might know how to get them off. It can't be the
first time the would have met the problem.
Let us know how you manage it.
Good luck.

John