BMW M4 Prototype

BMW is preparing its new M4 for a debut at the 2014 North American International Auto Show, and the final testing stages have apparently involved many, many laps of the Nürburgring. The only problem is, the two-door track star appears to have a case of the waggly tail, as spotted by a spy videographer. Generally, the serious nature of testing limits these sorts of shenanigans, but don't tell the test driver that.

Besides some tail-happy fun, this video is one of our first indicators of what the M4 will end up sounding like. There's certainly some classic BMW in that exhaust note, and it's fairly obvious from the upshifts that this particular car is equipped with a dual-clutch transmission. That fits with the rumors that the production car will go the way of Ferrari and the Porsche 911 GT3, by ditching the clutch pedal. Take a look down below for the video from Germany.