The white connector in the first picture looks like one for the old fashioned Blaupunkt stereos -
red = +12v
Brown = earth
grey/blue = illumination
at a guess I'd say the other 4 are speaker wires - although obviously there should be 8.
If there was
an old stereo in there before, the chances are it would have had only two speaker outputs. It may well be that the four wires you see there are connected to the 8 original ones and they are tucked up beneath the dash somewhere.
To fit the stereo shown you'll need a standard ISO harness - you can pick one up from ebay or Halfords -http://www.halfords.com/sat-nav-audio/c ... tor-pc3-08
and connect the relevant leads to what you have.