The first Ford Thunderbird with four seats was introduced. The four-passenger "square bird" converted the top-of-the-line Ford from a sports car to a luxury car. The new four-seater packed a 352-cubic-inch 300 horsepower V-8. Thirty-eight thousand cars were initially sold, making the T-Bird one of only two American cars to increase sales between 1957 and 1958. The T-Bird has become a symbol of 1950s American culture, immortalized in movies like Grease and rock songs like the Beach Boys' "I Get Around."