If your talking about the tail light lense being broken your going to have to change the whole assembly there not too expensive.I would try amazon and www. Rockauto. Com I got one for a 2002 voyager from rockauto they had a little better price but I would check both places. As far as changing it the 2002 was held in by a couple of plastic expansion push clips that you pull the center of it out about half way and the clip comes out. Yours might have a couple of screws or those push clips. You just have to open the lift gate and it will be right there. As far as why it broke who knows someone could have hit you in a parking lot some kids could have broke it who knows.