It was a sunny day in Berlin in November when this reporter anxiously got into BMW's newest car for a test drive. Which was appropriate, as the fuel inside the star was basically the same one running the car.

BMW had invited about 350 journalists from around the world over a two-week period to try out the Hydrogen 7, one of the only dual-drive cars in the world that burns liquid hydrogen.

Writers were flown in on business class, chauffeured to and from the airport and booked in luxurious hotels for a costly effort to spotlight BMW's bold addition to its flagship 7 Series, but it was also an impressive display of the elite automaker's determination to draw attention from hybrid, diesel and biofuel cars and promote hydrogen vehicle technology instead.