I use BMW Parts and BMW Accessories | Bavarian Autosport a lot. You should put the year and engine of you X5 in your signature. No knowing what you have for my X5 the offer the BMW version and also one by Delhi that is half the price. I haven't heard anything bad about the Delphi version.

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