One problem related to computer failure has been reported for the 2004 BMW 525. The most recently reported issues are listed below.
My navigation and radio system just stopped working and I had taken it to the dealership and they said that it was common for the car communications computer to go bad and that they would replace it for 1300. 00 and the fact that it was common that the part went bad that often was confusing and I think should be a recall for that part.