That is pretty weird about that van. I don't think it could get hot enough to dry a spot in the driveway. It must have been parked there before the rain started. Yes, keep cautious.

On another note, I am always amazed that you keep at the outside gardening activity through most of the winter!

I agree, even at the hottest parts of the van, the engine and exhaust areas, that would not dry out a wet spot. If there was any drying effect at all, if would have to be in a pattern, not the entire shape of the van. So the van must have been there for a while, still if the rain was more than just a mist the area should also have still been wet. Very strange! Did you check the porch for a package?

Hi Aspen, Seedfork, Yep, checked all around the house for packages, notes, whatever. Nothing. Nobody can figure it out. The only thing I can think is that there is an innocent explanation: it did look like a commercial van and I wonder if a workman arrived very early at what he thought was a work site (for remodeling or something), sat there for several hours (during which time it rained) and then realized his mistake when the workday started around 8 a.m. and left. We're keeping the place locked up tight just in case!

Sounds like a reasonable explanation. Glad you are keeping a cautious approach for a while though. Hoping it turns out that it was indeed something innocent.