1991 BMW M8 prototype outlined in all its glory

Before the current BMW M8, the automaker toyed with building an M version of the wedge-shaped E31 8-Series of the 1990s, even building a one-off prototype. That car recently resurfaced in a video from BMW Group Classic, including interviews with some of the engineers who developed it. The E31 M8 prototype has a version of the S70 6.0-liter V-12…