One item we will definitely have in the vehicle with us is my DD's old potty chair. We have used this before on road trips and will absolutely pack it this trip also. DD is four and has been potty trained for a very long time now, but we never go anywhere that she doesn't have to go "NOW!!". This usually happens just after we have been convenient to a clean rest stop or 30 minutes after we have stopped to eat. Of course, at this point there are no rest rooms around or they are too nasty to use. If you do decide to pack a potty chair though, don't forget the T.P.