[rhyds]

The problem with locking wheel nuts (Especially the really cheap and rubbish ones Rover uses) is that they're not really designed to take the full torque of tightening a wheel nut/bolt. You can try and lessen the chance of the key breaking by removing the locking nut/bolt first, then the other wheel bolts.

However, what guarantees that they break is that a number of "less than skilled" tyre fitters (especially at the national chains) just whizz up the nuts with an impact gun when changing the tyre, rather than using the correct procedure (that is wind the nuts in with the gun, but use a manual torque wrench to control final tightening)

Another fun part of wheel changing is when a car hasn't had copper grease smeared between the (usually alloy) wheel's rear face and the steel hub on the car. What this means is that the alloy electrolytically corrodes (essentially welds itself) to the hub. Removing the wheel then becomes very difficult, if not impossible, without heavy tools and a lot of swearing.