Minnesota Statutes Transportation (Ch. 160-174A) § 169.762. Pressurized flammable gas

Subdivision 1. Marking required. Any vehicle within this state which carries liquefied petroleum gas fuel or natural gas in a tank attached to the vehicle in any concealed area, including but not limited to trunks, compartments, or under the vehicle, shall display on the exterior of the vehicle the words “Pressurized Flammable Gas,” or a standard abbreviation or symbol as determined by the Department of Public Safety, in block letters at least two inches high. The letters shall be of contrasting colors and shall be placed as near as possible to the area where the tank is located.

Subd. 2. Dispensing prohibition. No person shall dispense liquefied petroleum gas fuel or natural gas into any tank in a concealed area of a vehicle unless the vehicle is in compliance with the requirements of subdivision 1.

Subd. 3. Penalty. Any owner convicted of violating the provisions of subdivision 1 or 2 is guilty of a misdemeanor.