At the preview drive of the 2010 Mercedes-Benz SLS AMG Gullwing in Germany, Editor-At-Large Arthur St. Antoine joined five-time German Touring Car (DTM) Champion Bernd Schneider in the SLS for an unforgettable hot lap around the 13-mile-long Nurburgring Nordschleife, the world’s most fearsome and challenging racetrack. Strap in and hang on…