It was done through diplomatic delivery (very similar program to that for the military/NATO sales); you can choose whether to buy the Euro-spec car or the U.S.-spec. If you buy the Euro-spec, you can option it out with equipment not available on the US cars, but then you can't take it back to the U.S., plus of course the price difference is quite large, esp if you want to pay in dollars and need to deal with Euro exchange rate. Since we were opting for every option available on the U.S. spec, the US-price was even better yet compared to the European ones which across the board price the options more expensive.
On the whole, the diplomatic delivery program is a pretty good deal thru BMW (this will be the 3rd one we've bought this way), although other mfrs, like Volvo, have better programs in terms of the price discount and how they manage the program/delivery. What I finally figured out in the end was that it was better to deal directly with the BMW Intl' Sales group rather than going through individual dealers as they often have no clue as to how the program works.