did some searches, no one has really had this exact problem. I bought my 2000 M5 in May, the PPI revealed a bad head unit. I made the selling dealer fix it, they used a refurbished unit. It worked fine minus it wouldn't eject the tape adapter I used for my I-pod. Other than that is serves it's function, radio and I can play I-tunes through the tape player aux adapter. About a month ago, I noticed the sound was only coming through one side only when using the tape adaptor/i-pod. Radio sounds fine, however I would have to switch between tape and radio until I got a good signal. Right after that I would hit a bump and my cluster gauge lights would go off at the same time the head unit would stop working(pixel OBC still works fine) hit another bump or accelerate hard and they come back on. NOW the gauge lights never come on and the head unit stopped working completely, so I assume these are on the same Bus-line? Sounds like the head unit took a crap, so might start with replacing and see how it effects the cluster issue. Any thoughts??