The Wisconsin State Patrol has been handing out a lot of unmarked Explorers lately. I always look at the license plate of a vehicle, however, and can usually tell the difference solely on that. Also, if I'm on the interstate and am going to pass a black or blue Explorer, I can usually tell if it's a law enforcement officer by the trim level of the vehicle. Agencies typically don't buy the XLT models (the highest trim level). On the other hand, in the village where my vacation cabin is, they ride around in "undercover" cars that have regular plates! Their patrol vehicles are fully unmarked as well; they just have a lightbar equipped and official plates as opposed to their "undercover" vehicles. I'm always cautious about my speed up there.