Usually commerrcial and industrial areas are pretty vacant at night, which makes any new vehicles stand out like a sore thumb. Both police and security know exactly which vehicles belong, and which vehicles don't. Trucks are the exception to this rule, because if they pull in after a warehouse is closed, they may have to wait until it reopens to unload.
While I think it is generally a very poor choice of location, an obvious RV or camper van is slightly less likely to be hassled than a cargo van or a box truck without credentials. With a window van, or even a more obvious camper van or RV, it is fairly easy to park in many areas along with other vehicles, and go pretty much unnoticed.
