I've been using one of these cabelas eat covers
Being that it's a one piece fabric over the seat back, when the tension is torqued down (to keep the fabric taunt looking), it applies downward pressure on the foam of the head rest. I guess over a 2 year period, the pressure on the foam was such that the foam was pushed through the metal rod within the head rest, leaving only the seat fabric and no foam padding between the back of my head and the metal rod. This should server as warning for anyone using this style of seat covers.
Now, where would I find a replacement head rest? any idea on pricing?