Ive started messing with 1.40 this morning (funny its the 9th, must have got a pre-release beta copy j/k). Anyway, I ran your playlist maker program and ran into a few problems. A few things to start off with though is that this is in my house, not my car and second, I have a drive for media (music, movies etc.) and a drive for my operating system etc.
1.) The first problem I ran into was when I tried to store the playlists in c:\autoplay\playlists. It built the playlists and everything as it seemingly should have but when I went into autoplay it just continually cycling through the playlist. Obviously because it couldnt find the files. I opened the m3u file and found out that it gave the music locations as c:\music\artist\album\songfile.mp3. Well, my music is at d:\music.
2.) Then I tried to store the palylists in d:\music\playlists\autoplay. I re ran the playlist program and it created about 10 playlists, then pops up the error message "Runtime error '76': Path Not Found" (i tried it several times, each getting same result.) Well, I was like, wtf but ok, ill see what it did with the few it created. On the ones it successfully created, they are missing song file #1 and one on album, it starts on song #10.
I swear Im not trying to gripe or anything, just wanting to pass all this on to you. Im sure many people use dual hard drives in their car setup so it might be a problem that many people will run into. Other than that, progressing along nicely. Im glad you didnt drop this even though you are swapped with work etc. Good luck.