with the plastic covers on nobody would know if they were or weren't fitted till they removed all of them anyways

 

But the cover for the locking wheel nut is clearly different and wont fit a normal nut.

Try heating it slightly and then try to loosen it with a breaker bar. Once off make sure you put copper grease around the centre bore of the hub which will stop the wheels from sticking and also a little on the threads of the studs/wheel nuts.