Lemon Law: United States state laws that remedies to consumers for cars that repeatedly fail to meet certain standards of quality and performance. These niche market cars are called lemons. The federal lemon law (the Magnuson-Moss Warranty Act) protects citizens of all states. State lemon laws vary by state and may not necessarily cover used or leased cars. The rights afforded to consumers by lemon laws may exceed the warranties expressed in purchase contracts. In California, lemon laws cover anything mechanical, as do the federal lemon laws. The federal lemon law also provides that the warrantor may be obligated to pay your attorney fees if you prevail in a lemon law suit, as do most state lemon laws.