German auto giant Volkswagen AG (NASDAQOTH: VLKAY) said this past week that in just four years, it will have 16 factories building battery-electric and plug-in hybrid vehicles around the world. It's a big step toward the company's standing goal to build 3 million electric vehicles a year by 2025. I think many investors have written that off as hyperbole -- but it's time to take VW's electric-vehicle effort very seriously.