1. Remove all plates All plates must be removed from your car prior to towing.
2. Return your plates to the DMVLicense plates can be mailed to the DMV or dropped off in person.
Drop your plates off in person. There are 3 ways you can drop off your plates:
A) Return them in person to any
MVA branch office, including express offices.
B) Return them to any
MVA authorized tag and title service.
C) Drop them in one of the MVA license plate return drop boxes. Currently, drop boxes with 24 hour access are located at the Baltimore City, Columbia, Gaithersburg, Glen Burnie, and Salisbury offices. Drop boxes are available during normal business hours at the Essex and Waldorf offices.  
Or mail the plates to:MVA CRTR
6601 Ritchie Highway, N.E.
Glen Burnie, MD 21062
Sending them by certified mail with return receipt requested is recommended. Note: When you return the license plates, always include your registration card.
3. Cancel your insuranceCancel your insurance after your car has been towed.
WARNING: Do not cancel your insurance until you are sure that the MVA has received your license plates. Failure to do so could result in a large fine. There is no fee for returning license plates.
Visit
http://www.mva.maryland.gov/ for more information on your state car donation laws.