The BMW 8 Series was a two-door coupe that went away in 1999. It returns 20 years later with three different body styles. Some might think it looks much like a Mustang (not really) or that it's more a 6 Series than 8 Series, but those are people that haven't experienced it. Tom Voelk drives the M850i xDrive coupe that won Automobiles Magazine’s Design of the Year Award. And then there’s that sound…