I have been building a music collection on my computer that consists of music from places like HD tracks and many of my cd’s converted to FLAC files. My new car has a nice audio system capable of playing 5.1 music. It has a disc player that will play dvd and dvd audio discs, but I would prefer to go disc less and feed the system from a high capacity mobile hard drive. (My stereo collection of music plays very nicely). i have been converting hires stereo Blu-ray and dvd tracks to FLAC files, but I’m struggling with getting the 5.1 files converted in a format that the car system will “see” and play? Anyone know what file format to use for this? Is it FLAC, m4a ? Please Help an analog guy in a digital world!