Although this may be a unique issue that will garner some helpful suggestions, to receive the most pertinent help, you should post the model, year and accumulated mileage of the vehicle you're having an issue with. At least if it's a gas or diesel engine. I can only assume from your post that your X5 has an automatic transmission.

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8/2011 X5 xDrive35d Sport, Black Sapphire Metallic, Black Nevada Leather, Fine Burr Walnut Trim
2/2001 M5, Jet Black, Exclusive Complete Black Walk Nappa Point Heritage Leather, Black Cubic Trim