BMW 5 series MULF Module repair - no radio, no bluetooth, no navigation etc. Called Revtronic who advised probably faulty MULF module. Told how to find unit in the boot. Removed unit and sent it to Revtronic using Royal Mail Special Delivery on Thursday. Confirmed receipt on Friday. Fixed and returned by Tuesday. Reinstalled unit and re-connected mobile through bluetooth - all working properly again. Thanks to Revtronic for the detailed phone help and prompt repair / return. Highly recommended for professional service.