I wouldn't jump to the conclusion that you need to 'de-sport,' may just be dead shocks and other suspension problems [bushings, etc.]. Mine has the sport package, fresh tires, and 86k on the odometer and I find the ride smooth and BMW-like. That said, I don't know what all goes into S226A on the build sheet - "sports suspension settings"

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2006 X5 3.0 6-spd w/Evo UUC ssk
sport/premium pkgs
born Valentine's Day, 2006.