NURBURG, Germany — With the standard Audi R8 headed for dealers, work has already started on what could be an even more powerful version of Audi's flagship sports car. Caught on the Nürburgring test track in Germany, this prototype shows several signs of tinkering by Audi's in-house tuning group.

Unlike the standard R8, this prototype's side blades have a slight bulge just ahead of the rear wheel. These larger air inlets suggest a more potent power plant may be nestled behind the seats. Audi's 5.2-liter V10 is the most likely engine, as it's already used in the S6 sedan. With only 435 horsepower, however, Audi's engineers are going to need to find a few extra horses to separate this R8 from the standard 420-hp model. Revised rocker panels are another sign of the prototype's tweaks, although the wheels and tires appear to be standard R8 spec.

What this means to you: You can't even buy a standard R8 as it is, so don't even think about getting your hands on one of these high-powered R8s when they arrive next year.

Modified Audi R8 Caught Lapping the Nurburgring