You're close. Your setup is the same as mine: root/MUSIC\ARTIST\ALBUM\song. For my 2012 Volt, the playlists need to be in .m3u format as you know, and they need to be placed in the USB stick's root directory. The key is that the listings in the playlist need to contain the entire path to the desired song, that is, MUSIC\ARTIST\ALBUM\song.filetype (note: these are back slashes, not forward slashes as you put in your message).
Someone previously advised changing the name associated with the USB drive whenever you make changes to the playlists or songs on the stick to make sure the Volt re-initializes for the changes. For example, I have mine named MYMUSICX, with X being a number from 1 to 9 that I increment each time I make a change (starting over at 1 again after 9).
Album art for my 2012 Volt (no MyLink) will only show if the art is embedded in the music file itself.
Someone previously advised changing the name associated with the USB drive whenever you make changes to the playlists or songs on the stick to make sure the Volt re-initializes for the changes. For example, I have mine named MYMUSICX, with X being a number from 1 to 9 that I increment each time I make a change (starting over at 1 again after 9).
Album art for my 2012 Volt (no MyLink) will only show if the art is embedded in the music file itself.