A 2012 Mercedes M-Class test mule has been involved in a high speed crash in Autobahn A81, which left a 26-year-old dead and the test driver severely injured. Apparently the driver of the Mercedes was doing a high speed test or something on this non-restricted part of the highway, as he ran into the man who apparently had crashed his vehicle into the guard rails.
Other than the Mercedes prototype, two other vehicles were smashed but none of the bystanders were injured. Back in 2008 Porsche had a similar calamity in which the test driver of a 911 turbo test mule crashed into the side guards at high speed and was killed. Maybe German car makers should do their tests in a more controlled environment than public roads!