The recovery in the American auto industry has moved into the fast lane. With gas prices at nearly $4, smaller cars like the Ford Focus, Nissan Versa and Fiat 500 flew off dealer lots in March and gave U.S. car makers their best monthly sales in almost five years. Larger vehicles sold well, too, offering more evidence of growing confidence in the economic recovery. Small businesses, farmers and others took advantage of big promotions to buy pickups.