Here's an interesting one. Apparently, a team of engineers failed to shut off the automated emergency calling system on a vehicle being used in a crash test facility in Germany, and as you may expect, it wasn't long after the dummies slammed into a wall that medical personnel were arriving on scene. It was reported that this incident was the first of its kind, as members of the Cologne fire brigade rushed out to what they believed was some sort of "massive" automobile accident. The firemen were able to locate the vehicle due to its integrated GPS unit, and while we're sure they were at least slightly confused upon arrival, at least they got to take the fire engine out for a leisurely spin.
[Thanks, Martin T., image courtesy of Edmunds