The endlessly increasing laws against the homeless is a perfect example of the servile society demonizing anyone who is living outside the conventional lifestyle. Aside from going full native, the best option is, as you pointed out, cleanliness, civility and not drawing attention.
If a vonuan, specifically van nomads, could work up rapport with his/her immediate community if normies it would help shape a good opinion of van nomads in general. Van nomads could act as traveling salesmen, providing goods and services so that when one rides into town the people get as excited as kids for the ice cream truck.