There is some additional checking that I would do.

First, I would try and find out why the engine was replaced. Was it caused by abuse? If abuse or neglect then consider what else might be getting ready to break because of it.

Second, if the replacement was really performed by BMW then there should be warranty. If there is no warranty, then why not. If not performed by BMW, then why not. Not that an independent couldn't do the job but I would want to know these details.

As an extension of the second point, if not performed by BMW then was it really a NEW engine? Someone could have just got it running and then traded it in. You don't want to buy a problem.

Who knows, you might end up with a steal but I don't think I would pay anywhere near retail, especially if my questions weren't answered satisfactorily and perfectly.

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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