i've been vanning-it with my cat, anouk for about 6 months, and i say hell yes to the litter box (and the rosemary tip sounds great)! i even traveled with two cats and two dogs in my van for a little bit, and it was ok. anouk wears a harness with a nametag on it all the time, and won't walk with a leash, but i did teach her to ride on my back for outings (i hold her leash in case she bails). she's an outdoorsy cat, and knows to come back to the van (in situations that aren't too chaotic), so when we're parked somewhere safe for a awhile, i like to let her out to wander. with morning and evening feeding times in the van, she knows to show up by dinner time. it's a little more complicated than traveling with a dog, but worth it, i'd say. i felt a lot better about keeping my cat in my life, rather than ditching her because i wanted to travel.