I'm not sure if it was my 90lb American Bulldog or my big but reaching to secure the car seat, but the passenger side panel is cracked and sags under very little weight. Anyone know if the panel can be replaced? We have never had the rear seats up, so I have seen people build a panel to support more weight back there, which I will probably end up doing...but, in the mean time, can I get a replacement piece, or is it part of the seat? :'(