heres the website , it looks like you were ok (
except )that you had your plate for 30k ....$100 is cheap compared to if you were loaded to your limit and they weighted you. the fine would be $1.00 a pound over the weight limit.......
NCDOT Division of Motor Vehicles: Driver Handbook: Chapter 1
If you are 18 years of age or older you may apply for an original North Carolina driver license. Under North Carolina's classified license system most drivers need only a Class C license to operate personal automobiles and small trucks.
Class A:Required to operate any combination of vehicles exempt from commercial driver license (CDL) requirements with a gross vehicle weight rating (GVWR) of 26,001 pounds or more, provided the GVWR of the vehicle(s) being towed is greater than 10,000 pounds. Also required for operating any combination of vehicles with a GVWR of less than 26,001 pounds, if the vehicle being towed has a GVWR of more than 10,000 pounds.
Class B:Required to operate any single vehicle with a GVWR of 26,001 pounds or more that is exempt from CDL requirements, and any such vehicle while towing another vehicle with a GVWR of 10,000 pounds or less.
Class C:Required to operate any vehicle with a GVWR of less than 26,001 pounds that is exempt from CDL requirements and is not towing a vehicle with a GVWR of more than 10,000 pounds. Most drivers need only a Regular C license to operate personal automobiles and small trucks.