After six year's absence, Chevrolet is back to IndyCar with winning engines. The company's motors were under the hood of the the top four finishers in Sunday's Indianapolis 500. "It is a matter of pride," Mark Reuss, president of GM North America, said Sunday at the Indianapolis Motor Speedway. "We've been through quite a tough time. People want to work for us again. That wasn't the case a little while ago."