Nuerburgring, Germany - Spy shots of a convertible version of Audi's R8 super sports car that is expected to be launched at next year's Frankfurt Motor Show have been revealed.

The shots published by Germany's auto-motor-sport magazine show a convertible with matt, black paintwork and vinyl roof during a test run on the Nuerburgring racetrack.

The car is expected to go on sale in the first half of 2010 but it remains unclear whether it will called Spyder or Targa, the magazine reported.

Overall the Spyder design is based closely on the R8 coupe but has the vinyl roof curving toward the rear without the small side windows. The engine cover has been redesigned with a longer boot. Technically the convertible is expected to be fitted with the same engine than the coupe with the 420 hp V8 motor.

The coupe currently sells for 106,000 euros (158,000 dollars) in Germany.

Audi has revealed a concept study of a V12 TDI R8 version but it remains unclear whether the car will be produced. It has an output of some 500 hp. (dpa)