I would try and buy it from the dealer that will be doing the servicing. Helps with the loaner car, but also gives you an advocate with BMW if you have any warranty issues. You only buy it once, but you will be having it serviced for four years.

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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