I've always referred to them as 'undesignated campsites,' but by whatever name it is the my favorite way to camp, along with primitive campsites. Fortunately there are plenty either variety near me (SE Washington State) and even more in Eastern Oregon.
My attraction to a converted cargo trailer was specifically for that kind of camping, plus the 'Stealth RV' angle when I'm on the road and can't find a good place to camp.
Speaking of, I frequently take trips that have me heading South on US 97 in Oregon. I've always had trouble finding a good place for undesignated camping between Bend and Klamath Falls. I always seem to get tired or it gets too dark around the Gilchrest-Crescent area. Should be easier on my next trip since I can just pull over on a side street, but any suggestions?
An 'RV' campground has no appeal to me. I camp to get away from civilization, not to be more crowded than I am at home. Besides, I'm cheap.
After years of motorcycle camping, often with little more than a hammock and a backpacking stove, and frequently alone, I'm embarrassed to admit I finally succumbed to feelings of being insecure out in the open.
So... The CT conversion is something I think of as a hard sided tent. Can't wait for it to arrive. The Forest River people who make it, added windows and insulation and other amenities for less than it would have cost me to do it myself. It's a 7 X 10 with V-nose and if it seems too big, I may order one more af a Tear Drop size. I already have mixed feelings about getting one big enough to stand up in since sitting room is all I really need.