When they separated the adaptive drive option from the sport package around '10-`11, not many people chose to pay an extra ~$3500 for it. Did you try looking at some 2010s and had better results? Downside to that of course is you won't have the newer idrive. Good luck with your search.

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'08 X5 3.0si - Alpine White / Saddle Brown interior
Specs: Sport Pkg, Premium Pkg, Tech Pkg, Comfort Access, Aero Kit, Style 433 staggered 20s on Conti DWS
Mods: Carbon 35 tint, LED angel eyes, GP Thunder 7500k fogs, H&R 20mm/25mm spacers, clear reflectors, gunsmoke-tinted taillights
Coded: Digital speedo, windows/sunroof/tailgate close via keyfob

X5 pics at Flickr