If you have the new Polar mod and that little bit of shifting of the back panel annoys you. Place a small bit of tape in the 4 places near the corners. I used the fancy industrial Kapton tape, but some packing tape would suffice if it’s not too thick. Place the tape right up to the edge of the panel. The thickness of one layer of Kapton tape was perfect to remove all slack so it won’t move in any direction. It feels as if the panel is screwed down now.