I have no specific inside information, but I suspect that there are limited opportunities for this model in North America.

While the X5d has done fairly well in the reported sales figures, the 3 series diesel has not. I don't know how the 335d sales figures compare to BMW's expectations, but they have even stopped putting the numbers in their monthly sales reports. My suspicion is that the numbers are pretty small.

Add in the lower volumes of the 5GT, and it seems like it would be very expensive to certify the 535dGT, amortized over the expected volumes. I think if BMW want to sell more diesels in passenger cars, they need to bring in the 20d in the X1, X3, and 3 series. That could build some volume.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue