The X5 lost positions because of the reliability ratings (mediocre). The review says that those scores are based on three separate JD Power rankings. Blame JDP. They did like the power, handling, and safety. They found iDrive confusing (heard that before), the third row seat to be a token gesture (agreed) and the price to be too high (OK).

The X6 got the same overall score, but because of a higher performance score, and lower marks for exterior design.

Overall the X5 scores were based on 52 separate reviews. They are simply aggregating data that is already out there.

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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