Of course the storage unit living has been romanticized in literature too, I recall the unit in Snow Crash being a whopping 600 square feet. A palace compared to the reality of storage unit and car living today.
600 sq ft is about the size of my apartment, which at market rate is about $3k/mo.
Illegal and in reality would only last a few hours into the night before security calls the police and you get trespassed. It's been romanticized but people have tried it and they didn't fare well.