I am not sure if this has been said but those spark plugs might be wet with fuel. I had this issue and I had to remove the plugs and dry them then the car starts(528I) Another issue is had was that the plug(connection between the computer and the engine was somewhat loose. Because if was loose, the car gave an hard time starting plus it would loose power in the middle of nowhere and shut off. After I 1. dry the plugs and secure the connection properly, the car runs and start fine. Its been almost 2 months now.

Again this is on a 98 528i auto.