The battery control module (known as the BCM or BNS) failed, triggering a fire. The incident occurred while the vehicle was parked in a garage and had not been operated for several weeks. The fire consumed the module, insulation on wiring connected to and close to the module, part of the trunk lining material, and burned through a total of five hydraulic lines (retractable roof hydraulics). It appears that the trunk seal limited air to the point that the fire was self extinguished. This is the only thing that saved the attached garage and house. The vehicle valued at $30,000 was determined to be a total loss due to the extensive repairs required to restore it to an operating condition. I have since joined a Facebook group "Mercedes BNS/BCM Fires" that has nearly 1000 members and found that this is a common issue with the Mercedes R230 model and fires have occurred dozens if not hundreds of times. We have determined that the module has undergone numerous changes, but there is no confirmation that any are safe. Mercedes refuses to provide guidance or solutions to this issue and apparently has no regard for the safety of current owners. I have retained the failed module, wiring, hydraulic lines, and burned portion of the trunk lining. It is available for inspection or analysis. I am a mechanical engineer with over 35 years experience in the automotive and industrial areas.