I put a sub in my hatch as I didn't want to chop up the panels for bigger speakers. Its removable in about 5 seconds with plugs I put on it, and I have a little amp near the spare tyre.
I think the 12 inch sub may get downgraded to a 10 in the future as its a bit too loud but with a set of 6 inch front speakers and the little 5's you can see I can hear the music really clearly, although I usually don't turn it up too loud so I can hear the car too.
In my last hatch, a set of Kenwood 7 x 10's just fitted into the side panel in the back and they were awesome with a little amp running them.
I have a Bluetooth head unit under the passenger seat in the front now I have no console.