This is pretty common in the Sunset neighborhood of San Francisco. Particularly because you only need to move your car (or RV) for street cleaning once or twice a month depending on the street.
A few years ago I helped my father sell our family's old RV, a 1978 Dodge Class-C 26 footer. It ran like a champ but was ugly as sin. The 20 year old girl that bought it had already finished her bachelor's degree and was planning on living in the RV in SF (with her 2 dogs) while she attended grad school. A couple years ago when I started dating my girlfriend, she was living in Outer Sunset (in an apartment), and nearly every time I drove to her house, I would see my family's old RV, in a slightly different parking spot.