Despite the stagnant employment numbers, the U.S. auto industry, just 24 months removed from a taxpayer bail-out, may be what keeps the nation’s economy from falling back into recession. After a massive restructuring and several high-profile bankruptcies, a leaner, more aggressive auto industry is making a comeback, hiring workers and ramping up manufacturing plants. From a trough two years ago, Ford Motor Co., General Motors Co., Chrysler Group and other auto companies have added almost 90,000 manufacturing jobs, a 14% increase, according to federal employment data. Many local automotive dealerships are also beginning to hire back some workers shed during the recession. Including factories, suppliers and dealers, the U.S. auto industry employs about 1.7 million workers and supports an additional 6.3 million private-sector jobs, according to the Center for Automotive Research in Ann Arbor, Mich. The center said those positions represent more than $500 billion in annual compensation and more than $70 billion in personal tax revenue.