I recently purchased a 2003 745i from a friend who is a used car dealer. When I drove it the first couple of times audio worked fine. Now nothing, no sounds. I have had it a few weeks now. It needs some love, but I love the car!!! It has a few issues that I'm addressing one by one. Last week I took it to BMW dealer to diagnose so I could have a starting point. They seem to think it is the Kombi going out. But aren't for sure. Technician pulled cluster think there was a disconnected wire causing the Idrive problems. Before I spend $2000 on their hunch I want to do my research. I have pulled the fiber optics and so far they all light up red. When in car you hear CD player cycling through, sometimes a staticky sound, and popping from rear driver side. No dinging from car when u open door. I have tried to check voltage thinking maybe bad battery but after I do the unlock (add last four of vin) and go back to the previous menu I hold down odometer button and the screen goes blank. It is an aftermarket Oreillys brand battery. Not sure if previous owner registered it. It tests good. From a Snap-on battery tester. I do get recharge battery on screen. I also have yellow parking brake and dsc malfunction. Other things on cluster seem to work fine. Speedo and rpms. I have the INPA program ordered and waiting on it to come in. Any suggestions would be appreciated. I just need to be lead in the right direction. I like doing the work myself when I can. Sorry it is such a long post.