Ignition Coils Failure problems of the 2008 BMW X5

I noted that the vehicle was not running properly so I took the SUV into an authorized BMW service center to be inspected and repaired. I was notified that the vehicle had experienced a burned up wiring harness from a short circuit to the disa valve on the engine. I was also notified that cylinders 1, 3 and 5 had failed ignition coils, which was the reason for the poor operating performance. I was also informed that the vanos valves were sticking and may need replacing. Prior to the poor running performance, last year we experienced the car filling with smoke and had to evacuate the children and adults from the car when driving the car. The car was inspected and no problems were discovered and the smoke did not return, no codes were found. A few months later, November 2014, the car suffered a "major drive failure" warning message and would not shift into gear from an engine idle condition. Car was towed to a BMW mechanic and inspected. It was discovered that a fuse had blown and was replaced without further incident. From an engineering and design perspective, no wire on a car should melt and burn, since fuses are required to protect the circuits to prevent that very event. BMW of turnersville, NJ completed the inspection under invoice #bfcs123894. I fell BMW should replace the failed wiring harness and disa valve, since it caused the fire by its failure.