In the hopes that this might save some time and be helpful to other fans of HD music, I wanted to provide an update on my own experience getting HD music in to my MS. I am a quasi audiophile at home and ordered the upgraded stereo for my Model S with the hopes that I could play my library of music in my car. All of my music at home is digital and is either in the format of full resolution AIFF files - ripped without loss from CDs and imported into my iTunes Library, high resolution FLAC files downloaded from services like HDTracks, and converted high resolution AIFF files from these FLAC files, imported into iTunes. iTunes will not play FLAC files. I have a library of some of these AIFF files on my iPhone, but the Model S will only access these via BlueTooth, with significantly diminished sound quality. After reading a number of posts, I purchased a Samsung T1 1TB SSD, a size large enough to hold most of my frequently played music. http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/portablessdt1/overview.html Another one that gets good reviews is the Oyen u32 Shadow. Oyen Digital: U32 Shadow 1TB External USB 3.0 Portable Solid State Drive SSD At first, I could not get the Model S to see the drive until I realized that the drive was formatted in exFAT format. The Model S will only read FAT32 formatted disks from what I understand. I corrected this by going into Disk Utility in the MAC OS and erasing/reformatting the T1 drive and reformatting it using FAT. Once I did this, the Model S saw the USB drive. In transferring files, my next discovery was that the Model S can read and play HD FLAC files (all the way up to 192kHz/24-bit), and all AIFF files ripped at standard resolution (44.1kHz/16-bit) but NOT any of the high resolution AIFF files converted from FLAC. ( I used Amarra by Sonic Studio for this). These files just produced a loud hiss. Perhaps a different conversion system would have worked better. And so, after a bunch of tinkering around, I now have access to all my audio in full and high def resolution. The sound a joy to listen to: very quite detailed, clear and warm. An impressive and a significant step up from Blue-Tooth, Satellite or Slacker. It would be great if Tesla would make this all a bit easier and create a better interface for HD music playing, but it is still worth the effort.