If there is no set charge, any voluntary contribution at the behest of the parker would not in itself be a true or substantial income. Insurance could just be treated as a guest visitor. But on the other side of it, I was once refused insurance cover on two campers being on my property, on the basis that they were a high value attraction to potential miscreants. Plus larger vans are less likely to fit into a city environment. We live close to a (small) city centre, and have 2 drives, one camper and 2 cars. Fitting another camper would not work, without the one or two of the cars being out on the road. Doable, I suppose, but not ideal.
