From another forum and even another brand, but might be helpful:
Ok, so I have an update on this.
I tried using Drivesort to physically reorder the files, but that didn't make any difference in the playback order. In the end, Strega7's suggestion was the one that worked. It is playing the songs in order of the Title in the ID3v2.3 tag. So I used the MP3tag utility to put the track # in as the first piece of the Title in the ID3v2.3 tag. I found more info from Nicu in the Toyota Camry/Solara section:
Flash Drive mp3 Playback
He talked about doing all the songs in one album, but since I have over 9000 songs, even an album at a time would take a lot of effort.
In the end, I was able to do all of the songs at once. I downloaded MP3tag from Mp3tag - the universal Tag Editor (ID3v2, MP4, OGG, FLAC, ...)
, then installed it and ran it. Then l clicked on the Directory field near the bottom and selected the folder that had all the mp3s that I wanted to load on my USB. It then walked through the folder and pulled in all of the mp3 files from that folder and all sub-folders:
You could also do this directly on the USB if you like - I just keep a copy on my hard drive so if anything happens to the USB I can easily copy it over again.
FYI - My files are organized into 3 main folders based on the mp3 bitrate. Beneath each of those is a folder for each artist. Under each artist I have each album, and finally under each album I have all of the mp3 files for that album. Despite all of these levels, everything worked great.
Next, I clicked on a song in the main window and hit Ctrl-A and it highlighted all of the songs (note that the files in the picture below have already had the Title updated to include the track #):
Then, go up to the Convert menu heading at the top, and select the bottom option, Tag - Tag. It will pull up a window to select the format string. Under the field, enter TITLE (or you can select it from the list by clicking on the right-arrow to the right of the field). Then go to the Format string and enter the following: $num(%track%,2) %title% (note there is a space between the fields). You can also use the right-arrow to the right of this field to assemble whatever format you want - just make sure to add the $num function to set the track number to 2 digits or track 10 could sort between tracks 1 and 2. Then hit the OK button on the Tag - Tag window, and it will go through all of the songs you have selected and update the ID3v2.3 tag so the TITLE field has the format you selected.
There is another thing you can do if you have the Year in the ID3v2.3 tag on your mp3s (which I do). I wanted the albums to play in chronological order if I selected to play all the songs for an artist. So I went in to the Tag - Tag Convert again and changed the field to ALBUM and entered %year% %album% (you can also use the right-arrow to the right of the field to add these fields from a list). If you do this, click OK again and it will again go through all of the songs you've selected and update the ALBUM field.
Once I had everything set up the way I wanted, I clicked on the Save Icon (floppy disk) in the upper left corner and it saved the files with the updates.
After that I was all set! I copied my new files to my USB and plugged it in. Some negative effects of this change is that if you're browsing using the screen interface, browsing by Albums will display them in order of Year instead of alphabetically, and if you browse by song they will display by track number, not name. So you'll get all of the 1969 albums first (browsing by album), and all of the Track 01s first (browsing by song).
Fortunately, since you can't really browse with the screen while moving anyway, I wasn't too worried about it. Why? Because you can still browse via your voice command system. And if you ask for an album by name or a track by name it will find it even though it has the number in front of the title. So if I want to play Hotel California, I just say "Play Song Hotel California", and it will pull up all versions of that song (in order of track number), and I can just select the version I want and play it. Same with Albums. You can also say "Browse Artist" to get an artist you want, then select the album you want (in year order), then select the song you want it to start playing at (in Track # order).
I did notice that it seems to take the voice command system longer to load all of the information than the screen browser. So depending on how many songs you have it could take a couple minutes to have everything loaded to the point where you can request any artist/album/song on your list.
In the end, while this ended up being a bit of an effort to figure out, this work-around does what I need and allows me to listen to my music the way I want. 😎