Hi, the problem you are submitting is not a problem. The stems on the bottom of the headrest are approximately 1 1/2 feet long, the back of the car is steel between the gas tank and the back seat. There are also metal rods in the back seat. Once pressure is applied to the head rest they freeze in between these two metal frame works. Once the headrest are in place there is no room for movement because the stems curve forward anyway into the metal seat frame.