If there ugly enough, no body will mess with them
Back in the day, my uncle used to leave 5 or so trucks and a loader at the department store he plowed. I remember he would always have to move them off the property by a certin date because of some tax issue with the store??? He really never had problems with people bothering them. I think one time, someone walked off with a few bags of calcium chloride, but that was it. Again, his trucks wern't anything special, but they got the job done.