We don't know much about this video, except that it's awesome.
For fans of German sports cars, it doesn't get more exciting than the idea of an original (E30) BMW M3 and a first-gen Porsche 911 chasing each other over some twisty mountain roads. Well, for the benefit of these enthusiasts, we have procured a video of just such a chase. We know very little about the cars apart from the year of the 911 and that the Bimmer is an E30. We don't even know for sure if the 911 is the famous original Carrera RS, built for just '73 and '74.
The license plates appear to be American, but that's all we have for a location (Blue Ridge Parkway?). If anyone has any further details, feel free to chime in with a comment.