Fabia 2012 Speaker/Sound System Questions

Hi all,

I've just bought a 2012 Fabia HTP 1.2 petrol (which I am delighted with!) to find that there are no speakers in the rear doors.  There are coves for them, with grills, but no actual speakers.  So, I have a few questions:

1. If I choose to buy speakers for the rear doors, is the wiring already there or will I have to run cables myself?

2. If the wiring is there, what speakers would people recommend?

3. If I upgrade the head unit, can anyone recommend a good one? I'm open to spending a bit more on a head unit with satnav, so if anyone has any recommendations for that, that'd be great!

Any info would be greatly appreciated!

Many thanks,

Chilli1