A lot of people are doing this now. There is a fairly large contingency in NYC surrounding area that have converted vans into living quarters because of the exorbitant rent. They move around frequently and have alarm systems and back up locks on the inside doors of their vans for safety. I’ve seen a few interviews with young women that have done this as well. They pay $10 a month membership to Planet Fitness (shower) and get free WIFI at Starbucks and other coffee shops.