I've got over 13k on my Sierra and I've had seat issues from the begining. Now it's just worse. At first, the local GMC dealer said it's normal -- they all do it. Next visit I had been feeling a side to side movement once in a while. They said they just put a clip in another customer's truck and they will order one for me. I am not sure what is going on with the seat. I know the plastic sides rub and squeek on the seat itself because it's too tight all the way around. It rubs on the the center console, too. I hopped in a 2015 Yukon in the showroom and it's the same design with the same issues I am having. The person in charge of those seats at GM should be in an unemployment line with the folks that let that bad ignition switch go in millions of GM vehicles. Poor design. Bet it won't be a problem in next year's models!