Hello from Holly Springs NC. I have recently purchases a 2004 330Ci and I love it. As does my 17 year old son. The one thing I need help with is the Radio/Navigation system. There are some big dots on the screen making it hard to see. Beyond that, I like to be able connect a audio devise with a AUX 3.5mm plug. Does anyone have any ideas on the best way to do this. I can get a new system, or find a way to connect a AUX plug to the existing system. In my old Mazda I was able to get an aux plug to work. Andrew
BMW does make a aux plug kit for this vehicle. But since you are having navigation screen issues your screen will likely have to be replaced. The radio you have is called a MK4 and there are some diy right ups on how to replace the screen but you could just upgrade the unit to a aftermarket one that looks similar and has all the ne tech. https://www.bimmerforums.com/forum/showthread.php?1730634-DIY-16-9-Navigation-Screen-Repair
