I was wondering if anyone is familiar with the power windows on an S 320. The car i have has soundproof glass (windows are thick) and the back door window has trouble going up and down and binds alot. You have to keep pressing the button up and down to get it to finally open and close. The motor appears to be fine, does anyone know if the tracks inside the door bend and have to be replaced? If anyone knows of this problem please write back.. thanks.