More than one locked container? How?
Notice: Maryland has a unit called, Maryland Coordination and Analysis Center. They have license plate reader cameras around the state that read license plates of vehicles. Some are connected to Criminal Background Check programs and Permit/License Holder lists from the different states that will supply them with that information. Do use caution when even driving through Maryland. They can know if you have a firearms permit/license without even stopping you. Other States most likely have a similar system.
Given their geographic location, I've heard they particularly look for Florida permits, which many people have.