Minor changes greeted 1972 Ambassadors, as AMC's biggest news for the year was the addition of the innovative AMC Buyer Protection Plan, that included the industry's first 12-month or bumper-to-bumper warranty. This was the first time an automaker promised to repair anything wrong with the car (except for tires) and owners were provided with a toll-free telephone number to the company, as well as a free loaner car if a warranty repair took overnight. This backing also included mechanical upgrades to increase durability and quality, such as the standardization of electric windshield wipers on all model lines, replacing AMC's vacuum-powered units, as well as better interior trims. By focusing on quality, the smallest domestic automaker was profitable for 1972, earning US$30.2 million (the highest net profit achieved by AMC since 1964) on $4 billion in sales.