Thanks for all the suggestions, my X5 has been at the dealer for a full week now and they still have not diagnosed the problem. On Tuesday, they suggested replacing the fuel pump. Yesterday, they reconsidered and today they are monitoring fuel pressure. The battery is new and was installed by the dealer 10 months ago and they say it is fine. I am driving a loaner 328 but miss the Xman. Will update asap. Thanks again.