The 'Ring's North Loop, a.k.a. Nordschleife, is considered the ultimate proving ground for production cars, with tight corners, high-speed straights, plenty of elevation changes, and hard braking zones. The only problem is that for automakers from the United States, i.e. GM, it's really far away, meaning that they have to spend lots of time and money to get their vehicles tested there while German marques simply stroll ten minutes down the Autobahn. So GM has added a 3.6 mile section of track to its Milford Proving Ground facility in Michigan, a section which directly mimics the (in)famous North Loop, with 20 turns and 98 feet of elevation tomfoolery. In order to keep it real, GM still plans to visit D-land twice yearly, but the wide range of situations available at the Milford facility will allow testers to better prepare the vehicles for trips around the original 'Ring.