I was putting my Winter alloys and tyres on today. The back ones went on fine but the front wheel bolts were extremely tight to remove and the locking one has sheared and the adaptor (key) just turns and turns with no grip now It seems to be both the inside pattern of the locking nut and the removal adaptor key that have sheared. Result being I have two rear winter alloys on but no front ones on yet ! Does anyone know the solution and how big a job to remove said nut ? I guess a trip to my Audi dealer is required ?