I just read about some guy in Street Scene Magazine that had "dice style" caps on his valve stems. At 55 mph one of the hubcaps came off but was held in place buy the cap. Beat the hell out of the side of his car and finally ripped the stem off and caused him to hit the guardrail! I guess the best thing to do is put the oversize caps on when you get to the car show and use normal sized caps when you drive. Thank God we all drive 55!