City of Bridgman issued the following announcement on Sept 5.
We want to remind our residents that if someone offers to seal your driveway for a small/cheap price, it's not only ILLEGAL but more than likely a scam as well. Our department was notified yesterday that a white color pickup was in town doing this. Unfortunately, we were advised about them AFTER they poured an unknown liquid (probably old or used oil) on a driveway & left after being paid.
PLEASE try to get a license plate number & good description of the vehicle/occupants, ASK to see a permit (which they are required to obtain), contact the police if you feel they are suspicious & NEVER allow them into your house! This same type of scam has been used for their "workers" to enter houses where money, jewelry & other valuables have been stolen without the residents knowing until it was too late.
Original source can be found here.
Source: City of Bridgman