Volkswagen (NASDAQOTH:VWAGY) is set on world domination: The German giant aims to become the world's largest-selling automaker by 2018, and it's not kidding around.

A big part of that push involves Audi, VW's global luxury brand. In this video, contributor John Rosevear looks at how Audi has become VW's secret profit weapon, funding the company's massive global expansion plans.

Motley Fool contributor John Rosevear owns shares of General Motors. Follow him on Twitter at @jrosevear. The Motley Fool recommends General Motors. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.