The folks over AMS have captured a prototype version of the forthcoming Audi R8 Spider performing test runs on the famed Nurburgring race track in Germany. Contrary to previous reports, the video reveals that the R8 Spider will use a traditional fabric roof top rather than a lift-out targa top. According to Carscoop sources, apart from the standard R8’s 420 HP 4.2L V8 engine, the Spider will also be available with the RS6’s 580 HP 5.0L twin-turbocharged V10 engine which is being readied for the coupe variant in 2009. The R8 Spider is expected to make its debut at next year’s Frankfurt Show in September. -Video after the jump