I'm getting ready to put new foam and cover on a used seat pan. I took the old cover and foam off tonight and noticed that there is some additional padding in the front and on the sides of the pan. Its stuck to the pan and its kinda like carpet padding. Is this add'l padding supposed to be there underneath the foam? Do I leave it or remove it? If it isn't OEM, I think I'll remove it. I hoping to get this seat done tomorrow.