The vehicle is illegal. ANY unauthorized use of a registered trademark is illegal, just like copyright violations are illegal. If a police officer has any concerns about a whether a vehicle is actually authorized by the company whose logo it displays, this should be fairly easy to verify with large companies like FedEx and UPS, as well as with local utilities. Those companies know where their vehicles are supposed to be at all times. And sensitive locations, like government or military sites, fuel storage sites, etc. generally have a security guard in place to stop and identify vehicles before allowing them to proceed. It’s probably time to step up verification procedures.
I think you’re absolutely right. In addition, most big companies now have electronic tracking of their vehicles, so an inquiry should reveal immediately whether it’s genuine or not.
I don’t think the druggies or human smugglers will keep on doing this for long, simply because now that it’s a known issue, corporate trucks are going to be subject to more scrutiny. Personally, I’m more worried about the one-off type of use - that is, long enough to get into a secure area and blow up.