Are you talking about the Nav Unit or the base radio or what?

 

Nav unit

 

There's 3 modes; Play in Order through all folders (DEFAULT), Shuffle through folder, Shuffle through ALL folder. I have mine set to SHUFFLE through ALL FOLDERS.

 

How did set that

 

So experimented

Put a USB with 3 folders with 2 songs each

Could do it manually by pressing LIST > then Click on folder name in the middle whoch got list of folders
I then tried to make it via the steering buttons
So if I pressed and hold the up or down for few secs, it rew/fwd, if I quicly pressed UP UP, it actually changed the folder
I had read but just found you can add the mp3 to the internal HDD, size is about 6GB called MyMusic

 

Interesting

 

Do you have those 6 folders within 1 main folder?

 

No seperately