I am intrigued by the series of small rectangular panels around the truck body. They do not appear to be painted on, but rather either picture frames for holding print media, or transparent viewing ports for looking into the van. They might even be ports holding CRT screens, but the placement doesn't look right, and, unless they were added later, the the date of truck manufacture looks too early. Are these panels significant to the puzzle solution?
Also, I may be completely wrong, but I think I see what looks like a very small model car toward the lower front of the van body in what looks like open (openable?) area under the panels mentioned above.
