Hi can anyone tell if the Skoda Columbus stereo/ sat nav will fit my 2006 mk2 octavia vrs, if it does do need any extra wiring or parts

Yes it will, mine was a direct replacement for the Stream HU before it. It's just plug and play too so no complicated wiring changes. But you do of course need a GPS antenna.

...and you'll need the suitable dash surround to go with it as it is a different shape to the Stream HU, plus more than likely coding to the car if you have a maxidot and steering wheel controls.

Ian