Mystery Nürburgring Roadster Identified?

There's a lot of buzz nowadays about secret prototypes testing their on-track capabilities on Germany's famed Nürburgring. But while most cars are easily identifiable despite their heavy camouflage, this silver roadster is just sitting around undisguised, and we still aren't exactly sure what it is. This clear shot… » 5/05/08 3:00pm 5/05/08 3:00pm