Preston BMW

The BMW 6 Series has been a tight-knit family of executive coupes since the first model launched in the late seventies. As with most things, that survive consumers' mercurial preferences in the long term, the BMW 6 Series has evolved subtly, over the years. For, the 2013 model year, however, the Bavarian automaker is adding an all-new variant that looks more like a cousin to the current 6 Series models than a sibling. The imminent…