Sony music system in my car reads files in the order they are stored on the flash drive , which is very stupid in my opinion. Ideally it
should read the file in some alphabetical order or based on the last modified date. I found a program call DriveSort which reorganizes the files on a drive so they are in alphabetical order.
Download this program from the location http://www.anerty.net/software/file/DriveSort.php
and open the drive. After this sort the files and save the directory.
Please also refer to this URL for more details on this