For the third straight year, C5-R Corvettes migrated south to compete in the crown jewel of North American sports car racing, the 12 Hours of Sebring. And for the third straight year, success at Sebring once again eluded Chevrolet’s factory racing team.
   Corvette’s problems in previous years have covered the entire spectrum, including damaged bodywork, failing brakes, inadequate tires, broken transmissions and differentials, and defective engine parts. With two years of racing behind