No, The lowering kit comes with new front springs to lower the front. To lower the rear there are links on each side that attach to a electrical connection. That connection tells the vehicle how much to increase air pressure to bring the X5 up to spec height. The link is adjustable so the shorter you adjust the link the lower the backend will be, in other words, the shorter link fools the self leveling system into thinking the backend is at spec level. The OE link is not adjustable.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas