The Monroney Sticker Law:

The Monroney sticker or window sticker is a label required in the United States to be displayed in all new automobiles and includes the listing of certain official information about the car. Since the mid-seventies the U.S. Environmental Protection Agency provides fuel economy metrics in the label to help consumers choose more fuel efficient vehicles.

The window sticker was named after Almer Stillwell “Mike” Monroney, United States Senator from Oklahoma. Monroney sponsored the Automobile Information Disclosure Act of 1958, which mandated disclosure of information on new automobiles.

Since 2013 a more comprehensive fuel economy and environment label has become mandatory.  The new window sticker includes specific labels for alternative fuel and alternative propulsion vehicles available in the US market, such as plug-in hybrids, electric vehicles, flexible-fuel vehicles, hydrogen fuel cell vehicle, and natural gas vehicles.

Chapter 28, Sections 1231-1233, Title 15 of the United States Codes makes the Monroney sticker required and affixed to the side window or windshield of every new car sold in the United States and can only be removed by the consumer.

A fine of up to US$1,000 per vehicle for each offense is authorized if the sticker is missing, and other fees and penalties are authorized if the sticker is altered illegally (including imprisonment).  The act does not apply to vehicles with a gross vehicle weight rating (GVWR) of more than 8500 pounds (3856 kg).