I used to carry a Trunk Monkey, but they fell out of style. I think PETA caught wind of it (People for the Emancipation of Trunk Animals.)
No trunk but we do keep van suppled with a few things, don't have to stop except for gas every 500 miles. take along food when traveling. We have a bed, potty, cooler, small fold away table, 4-fold up chairs. Here in the south rest stops can be dangerous. haven't stayed in a motel in over 50 years. We camped out in campgrounds before the nation was invaded, now no vacancies. I've had a van since the late 60s.
In the winter, here in Maine, I like to carry a 100% wool blanket in a plastic bag. A wool blanket will go a long way toward keeping someone alive in freezing temperatures if I should get stranded somewhere.