I've searched but all I can come up with is seat squeaking. Mine doesn't squeak, mine pops and clicks under acceleration and anytime force is applied to the back portion. I've inspected the seat and it appears the seatback pocket area is coming apart from the seat itself! Has anyone had this issue? Could this be the cause?

 

You should go to the dealer if you are still under warrenty. I never heard of that....good luck