A 911 prototype testing ended with a tragedy: a 51-year-old Porsche engineer died in Germany this morning. He was driving the car on the A5 Autobahn when he lost control and slammed into a guard rail.

The one-car accident happened at 2:45am just past the Weiterstadt exit on the motorway. According to a Porsche spokesman the engineer "was one of the most experienced test drivers." The company representative confirmed that the car was a camouflaged cabrio covered with foil to mask parts of the vehicle's appearance. He also noted that, although it did not rollover, the convertible does not have the same resilience as a coupe.

Causes of the accident are unknown yet. The engineer was driving at a high rate of speed. That stretch of road does not have a speed limit. He was being followed by a second Porsche testdriver in a camouflaged four-door Porsche Panamera prototype.

.