Started noticing the issue in mid may 2016. i don't usually move my seat from the original position of comfort but driver seat has shifted inadvertently sliding forward or back without warning while driving (15 - 50mph). along with the seat belt on occasion unbuckled while moving sometimes in conjunction with seat movement, other times alone. this has happened several times lately and i have taken more care to hear the click & tug on belt but this sometimes doesn't make a difference. while driving on interstate (up to 75mph), a shifting of weight in seat, or looking over shoulder for traffic while changing lanes can pull clip out of clasp.