I don't understand the hesitation to tow in the OP case. If I'm house-sitting for someone and a vehicle shows up without authorization, I have no problem calling it in. Of course, when I house-sit (and it's only been a couple of times during hurricanes) I get a short note signed by the neighbor saying they give me authority over the property in their absence.Driveway owner needs to drive up in the middle of the night unexpectedly, find the truck there, Gee WTF did that come from?, call Po-Po and tow truck. Have it hauled away.