My Volvo V50’s mp3 player is able to sort the folders it finds on the flash drive I plug into it, but is unable to sort the mp3 files in the folders in any useful way. It seems like it just plays them as it finds them on the file-system. This week I found a utility that sorts the files on the file-system, called FATSort. If you’re a Linux user, make sure the names of your mp3 files start with the track number (01, 02, 03, …), install this utility and run it on your flash drive’s device. Your car will now play your music in the order it was intended to be heard.
If you’re a windows user, this utility seems similar, but I didn’t test it.
I hope this helps a fellow Volvo (or other) owner out. Happy listening!