Head Unit connectors and new head unit

These are the connectors that my previous head unit was using and I can't help but feel it could do better. The new head unit works well, I have set up the steering wheel controls and a USB microSD card reader is on it's way so I can add a load of music to it (and not have it playing off my phone all the time).

With the replacement head unit I also got this additional connector set:

The car (2005 facelift) has these additional connectors (sorry it's not the clearest):

So my question is whether there is some way to connect the extra connectors to the unused connectors in the car - I am assuming that some must be connected to speakers that aren't currently being used.

Am I chasing a dream or are any of these connectors actually going to be of some use?

Hopefully someone can let me know.