We have three cats and they travel in in the truck (crew cab) loose. They all have harnesses on which we use whenever they go outside or travel. There is one bed on the back seat an old top sheet covering the entire seat and a small litter box behind the driver in case of an accident.
Choose an RV based on what you need/want then see how ell it works for the cat. You asked about the cats moving around while driving; well depends on the cat. We have one (Bandit) that sleeps the entire time and doesn't move until dinner time (sleeps through lunch breaks). The other two move around when they are bored. They do take turns sitting on the console but for the most part they want a stable base to sit or lay down.
