deblyle

I'm just as new to the AVIC scene - I have a Z1 that came with my recently purchased used car. The prior owner said the drive was unlocked but did not provide much guidance on what I could do with an unlocked drive. I definitely thought I could copy music/video to the HDD like you can to a PlayStation 3 if you know the proper directory structures. Is that possible, if yes, please provide a link on how to. Secondly, I read you can upgrade a Z1 to a Z3 - I assume that is via firmware, what functionality would I get with the upgrade - reason to do it? Thanks for your help to a neophyte AVID