The Nurburgring is meant to challenge car and driver! Learn the course (this is important) and learn your cars capabilities (also important). There is not such thing as the perfect car for any course, only the right driver! You might as well be asking "What's the best sport bike to drift with?" Doesn't make sense. Learn the track, learn your car, and watch your lap times get shorter. Best way to learn the track is the AMG Driving School, the Grey AMG car is perfectly tuned for that track, try it, i learned the Nurburgring very quickly, especially with the constant restarts. It starts you off in each sector so you can learn that spot before you do the whole track together. GT5 isn't meant to be cheated on, it's a racing sim so people can adapt themselves to tracks like real world drivers would. They don't go to their team managers and ask for the best car, they drive, tune, drive, tune, drive, memorize, drive, tune, memorize, etc.