Just signed up to share my story...2016 GMC 1500 All terrain that I had GMC put together for me with the 6.2L motor, Borla exhaust, 22" rims. Told the dealer this was my very first new vehicle that I was treating myself to for my retirement. Truck is awesome....except the seat shifts slightly to the left and right when turning. I have had the truck to the dealer numerous times, and I admit it is not the mechanics fault that GM cannot design a seat. Finally after going over the truck yesterday with 3 mechanics and being told this was a normal condition, I think I found the problem. I am 6'3 and 215pnds. The mechanic was 5'7 and 160. He couldn't feel The seat shift on turns. They replaced the seat cover because it "stretched" I have leather interior. If you look under the seat, the cover holds the seat cushion in place with clips. I can grab the front two clips and move them slightly left and right, and by doing so the seat cushion moves. The design has the clips on a flat bar allowing this shift with my body weight. Two U shaped plastic clips on a I shaped painted metal bar with no lateral pinch points to stop the movement and you can see the problem. The dealer epoxied the clips in place to stop the movement in both driver and passenger seat. Picking up truck today. Finger crossed.