Maybe it is due to all the years of sitting on the seat....perspiration from your body will often transfer from your body to the seat making it stiff. You might consider looking at products offered from Leather Z. I use them and they work for me. They do have products to fill in cracks, but I do not know if it will be applicable to vinyl...assuming that's what the seat panel is made from??
Last edited by morrieschoice; 11-20-2012 at 06:04 PM.