This is 8-5 week day stuff. Look for guys doing this on the clock using a company truck/van and then being off on the weekends. They have a daily route or are dispatched to job locations. They will be sort of like the Invisible Man in the short story of the same...note Mailman in the story. Hide in plain sight.
Don't think so. Reason: timecards too easily traceable. Someone at the home office dispatch would be more likely to notice a discrepancy or pattern in the unassigned time or delays to the next job(s).
They're using animal-appearance-style mimicry imho.
The way to maximize invisibility is to look like a company truck but not be a company truck. Presuming these guys have the bucks to spend on various sniper niceties, it is not a large leap to imagine them having about $5K cash to invest in a secondhand white panel Isuzu or Mitsubishi truck (note: I saw one response that mentioned the truck had a black mark on the side; I got the vague impression that the mark was of the type that indicated a minor accident, and if so, the value of the truck would be decreased, making it more economical to purchase).
Since no leads have turned up in the rental area, at least none that have been reported, and they would have been stupid to rent anyway (note: not saying not worth checking out, but I would not expect much in way of results), I think the easier explanation is they own the vehicle(s) free and clear and could choose to move it, paint it, abandon it, ditch it or torch it at any time with complete independence and impunity.
An ideal setup would be a small van with a couple of single rider motorcycles lurking within sight. If the van is cornered, the guys could jump ship and get a quick rescue from the more mobile cycles. That presumes there are enough people and cash resources to cover such backup planning...
Hitting a schoolkid from a nearby forest may imply that they had to ditch truck when it became too hot, and had to use a different MO to reach out and touch someone in a way that would still minimize chances of getting caught.
Always possible I might be completely off base though...