I picked up the X3 tonight. The dealership is not sure what the problem was. BMW had them run a series of tests over and over again. The notes on the invoice indicates that the "Test Plan" froze twice and they eventually cleared the fault codes. Another note at the beginning states that the "Oil is at the proper operating level and does not appear burnt at this time" but then there is a later note that states "Topped with one liter of 426 fluid." Why would they top it off with one liter (seems like a lot) when the operating level was normal to begin with?
When the service advisor called me today he basically just paraphrased the notes on the invoice and couldn't tell me what the cause was and what they did to fix it. There is a note in another section that reads "Programmed and encoded vehicle control units" and I'm wondering if that was essentially a reboot of the software. The service department was closed when I picked up the car so I'm going to have to follow-up with them tomorrow.
The transmission did a really abrupt shift at low speed on the way home (which it had never done before) so I'm not convinced it is right. I'm going to have to take note of everything over the next few days.
Thanks to all of you who offered thoughts over the past week. I appreciate it.