I was switching to my summer rubber and when I went to remove the lock nut on the rear wheel it snapped off at the head. I guess there was a crack and rust got in there and caused it to break. The same thing happened to me last year. Anyone else with this problem? Also last year when it happened mazda replaced the lugs with a set ooff the lot, this year they are tellign me that it is not a warranty covered item. Any insight anyone?