Tamid, I like your term Urban Boondocking.
I'd be concerned about exposure to or risk of robbery and or assault or exploited by other transients if I were "camped" out on a full time basis.. in an out-of-the-way location in a vehicle not really marked as a camper
Stealth camping to me is while traveling to be able to pull in a parking lot or similar place Hospital, 24 hour stores etc. and park in and among the other vehicles without sticking out or giving that "I'm sleeping in here look"
Out of the way places i would feel more comfortable looking like a camper (put out chairs, ..... I even thought of magnetic signs with flowers or something to make it look like a camper as i agree with what you say.