When I go offroading my dogs bounce off the unpadded walls and roof of my VX with no ill effects. Dogs are really tough... they won't feel any pain from a little jostling. (As an example, have you ever seen a dog force a sliding glass door opened with his face while you are trying as hard as you can to hold it closed? Unbelievable; and my dogs only weigh 30 lbs each!) As for keeping them back there I just flip up the rear seat against the front seats to form the wall you want. Maybe you should just put the seat back in!