Donna D had some good advise. Stealth Camping IMO would be easier in a Van, just because it is smaller and may not look like a camper right off.
Way back when, we had a Chevy pickup with a shell/cap camper which we did some stealth camping. The only real time where we were not suppose to stay, was at the Grand Canyon South. No room at the campground, on the way out along the rim road somewhere not by the rim, but in a section of forest we saw a forest road going off. Just a little off the main road but with a screen of trees and plants, we pulled in and leveled it as best of possible. We spent the night, no-one the wiser, as far as we know. We did not use a lot of lights
, had curtains on the windows
We were in our 20's and it was around 1972 or 1973. In this day and time, I would not try it again.
We would try one of these if possible: http://www.freecampgrounds.com/
Or find a Wal-Mart: http://www.allstays.com/c/wal-mart-locations.htm
and others like Flying J, K-Mart, Sam's Club, Costco, Target, TA Travel Centers, Pilot Travel Centers, Petro Stopping Centers, Loves Travel Stops and Cracker Barrel sometimes will allow overnighting. My son and his family plus my daughter spent a night at a Target in OK in May and a Wal-Mart in SD plus a state park in Neb.
Califonia has the Enroute Campsites at some of their State Parks/Beaches:
We go for more comfort in camping/overnighting now days. We wanted our shower and head with us.
Even the US Air Force are retiring their stealth fighter air craft.
I also agree with the comment on "Dogs can sense danger" and would add they will protect their owners/pack members. You bet!
A single shot 20 or 410 GA shot gun would be a big help in a time of need and not be as frowned upon by the police as a pistol.
I have looked at a few but not gotten one. Yet.
Correct me if I am remembering this wrong. In the book "Travels With Charley" by John Steinbeck, one night he stepped out of his pickup camper with a shot gun after being worried with some people as he was over nighting at one point in his travels. In 1960, Steinbeck bought a pickup truck and had it modified with a custom-built camper top -- rare for that day -- and drove across the United States with his faithful poodle, Charley. It has been credited for the boom in RVing from then on. I read it back in the 70's and enjoyed it, I already had a pickup with the camper shell on it by the time I read the book.