The roomy 3 Series Gran Turismo recently went on sale in China, where many luxury-car owners prefer to ride in the back seat. Photo credit: BMW.

Luxury cars are big business nowadays. Not only are sales of luxury vehicles booming around the world, but they're generating immense profits for the companies that are successful in this space. There's a reason that General Motors (NYSE:GM) is spending billions to elevate its old Cadillac brand, and that reason starts with GM archrival Volkswagen (NASDAQOTH:VWAGY) -- which makes billions from its Audi brand every year.

Of course, Audi is locked in a brutal battle with its German rivals, and so far this year one of them -- BMW(NASDAQOTH:BAMXF) -- has the edge. In this video, contributor John Rosevear looks at the latest numbers in the luxury-car wars from the U.S, China, and elsewhere -- and at what's at stake in one of the fiercest battles in the global auto business.