I took out the aftermarket Pioneer stereo that the previous owner put in and re-installed the BMW Business stereo. The sound is good, the steering wheel controls work again and my dash looks nice again. One problem came up and that is the 6 CD Changer in the trunk seems to be intermitent. First, it showed "No Discs", then after poping out the cartridge a couple of times, it saw discs in slot 3 and 4 and then played all of the positions. Now it sees no discs again. Any ideas? Wiring harness loose in the front? The back?