Ahaaa-ha thats the reason. The carpet we were using was not rubber back. It was cut to size in 1 peice very thin cheap stuff from HD that I used for the headliner on my Polaris. It was easy to just pull out and shake clean then with it's memory it fell right into place. If you can't even use that and rubber back is worse, what can you use?
After reading that artical they say rubberback but also heat if I read correctly. As I said the rug we used was not rubberback so I would assume it's just as much a heat problem. It's worse at the door where the little lower window is and farther in it gets better.