Mine 2001 x5 3.0 has had the same issue for a couple of years. Tried changing fuel filter to no avail. Did try the start up in many posts where you turn key to first position for maybe 10 seconds then try cranking. This works for my x. Starts right up when i wait. Dont know if that points to an electronics or mechanical issue. And that comment about dealers annoyed your not in a new X5 is so true! I just imagine when we drive up they are thinking oh hell, wonder which out of hundreds of the same documented issues is it going to be this time!