Hi, My E46 M3 is a 2001 model. It has the BM54 unit (at the moment removed while I was trying to find a different problem) I have the widescreen in the dash, but the nav part from the boot has been removed, so just have the changer in the boot. So I have a couple of questions, if someone would be so kind as to help. Without nav, would it be worth upgrading the BM54? Regarding my set up, would I be able to play an mp3 / usb / hd through the unit in anyway? I have noticed that radio stations are great while stationary, but bugger off when I move, is this fixable? Again with my setup. Thanks in advance.