One problem related to engine shut off without warning has been reported for the 2004 BMW 745. The most recently reported issues are listed below.
I was driving on the expressway and everything went haywire and all the lights came on and the engine felt like it shut off. After I pulled over I shut it off and tried turning it back on but it wouldn't start. I sat on the side of the road for 25 min and tried it again and it finally turned back on.