It occurred to me the file structure might not matter. I commented on that somewhere along the line. However, using a logical structure (Artist>Album>Song) makes it infinitely easier to know what's on the drive.
I need to add emphasis on should. IOW, it works in my Jeep. I did the same thing with someone's Ford and it refuses to play anything. Of course, Ford and Lincoln are the same company.
I am 100% Mac, and as long as your car can play ALAC, then you should be able to copy over, intact, any non-DRM music, using the same file structure as iTunes and have it work perfectly. iTunes does add full meta data. In my case, I take the ALAC or FLAC files and convert them to 320kb/s mp3...
Ron, as long as you maintain the same file structure on your drive (Artist>Album>Songs) then YES. It also needs to be in the meta data of the files. The first time you insert the drive the car usually indexes it, which can take several minutes. In my car, after that it's maybe 30 seconds...
BTW, I got one of THESE thumb drives, which are so crazy small they barely protrude beyond the USB slot. Only enough to have something to grip on. Max of 512GB, but I do all 320Kb/s mp3s in the car, so plenty of storage. I used to use a 2.5" SSD but this thing takes up no space.
Ron, for DRM music, your current solution (playing back with the DRM compatible iPhone) is the only option I'm aware of. I have no DRM music, so for me it's not an issue. My music is all from CDs or purchased from HDTracks, which are DRM free.
Or, you can load only non-DRM music on the drive...
Does the car have an analog input of any kind? I seriously doubt it would provide any tangible improvement, but if you wanted to try it, you'd probably want a headphone DAC. The type that connects to your computer and you plug your headphones into. Adapting the iPhone to that might be a...