Tuning your prototype M5 at the Nurburgring can be problematic due to the spy photographers. That is why our friends at AC Schnitzer took their latest BMW to Saxony. The Sachsenring dates back to 1927, and it has been home to the East German Grand Prix. During the Cold War, this was probably slower than watching paint dry. &feature=youtu.be But now it is home to manufacturers who want to keep their projects away from prying eyes. So the latest M5 prototype was tested by AC's engineers this week. What they recorded was the fastest lap by a sedan at this track. Veteran racer Jörg Müller ran 1:31.71. This is 4 seconds faster than any previous sedan, and they are not yet. As of this morning, their mean M5 is making 700 horsepower and 627 lb-ft of torque. If you would like to experience this level of power, click the link below to find your M5.