Thanks to a trip to the BMW Museum in Munich, The New York Times discovered the BMW logo is actually based on the colors of the Free State of Bavaria, not a spinning airplane propeller. As it turns out, the association between the logo and an airplane propeller stems from a 1929 advertisement - a full 12 years after the logo was trademarked.
"The design was not in any way connected with aircraft engines or propellers," according to a history published on BMW Motorrad UK. "The idea that the blue and white had anything to do with spinning propellers comes from a 1929 advertisement, which featured aircraft with the image of the roundel in the rotating propellers."
The BMW logo was actually created in 1917 as a tribute to the Free State of Bavaria. However, at the time it was illegal to use national symbols in commercial trademarks, hence the opposite order of the white and blue quadrants.
Making everything official, BMW North America spokesman Dave Buchko has confirmed the logo is not based on a spinning airplane propeller, but rather the colors of the Free State of Bavaria. Kind of makes you feel like up might actually be down, no?