In the next month or two I want to replace the 'Stream' car stereo head unit in my car but cannot find any comprehensive information on doing this for the Octavia mark II.

So far I understand that I will need the following items:

1) Aftermarket Head Unit of my choice - I have one in mind.

2) Fascia adapter to house the DIN head unit within the Octavia dashboard.

OPTIONAL - Secondary DIN compartment to fill the gap if the fascia holds dual-DIN

3) Wiring harness adapter to connect the Skoda car stereo connector to the ISO connector for the head unit.

At this point you would hope that to be all but do I need,

4) Radio aerial amplification adapter.

Also, the car comes with a 6-CD changer. I haven't checked its specification properly but I suspect it is a standard VW/Audi model. Since this is currently controlled by the Skoda Stream head unit is there any chance I could make it work with the new head unit? Will I need a,

5) (CAN)Bus controller adapter or something similar.

I am pleasantly surprised by the sound quality of the speakers although I may add a subwoofer at a later date. For now I just want a new head unit that can play compressed digital music and control the CD changer if possible. I had no problems installing a new head unit in an old Audi A4 but this is more complicated. Any help would be appreciated.

I believe that you need a wiring adaptor to go from the CAN-BUS connector to ISO and you can get these with the aerial adaptor included.

The fascia adaptors are obvious , but I don't think you'll find anything that will control the factory fit changer

When I ordered my Octy2 last year, I asked the dealer to fit my own single-Din sized sat-nav unit instead of the standard head unit.

They needed a fascia adaptor and can-bus adaptor.

The part numbers were AZ0600003 "Double Din Octavia kit" (doesn't specify which Octavia) and STC857CAN "Plug and Play Canbus Anal" (honest, that's what it reads!).

The double-din adaptor provides a cubby hole under the radio and even has its own little rubber mat. Yes, the fascia does take double-din size units.

See all the other comments regarding the aerial. Since you're not removing/changing the standard aerial (are you?), then the Skoda canbus adaptor should make sure that the power is still drawn from the new head unit to power it (the amp is built into the aerial, if I've followed everyone else's posts correctly).

Be aware that you may still need to rewire the ISO plug -- I did, because there was one wire connected to the phone-mute terminal on the HU. Still haven't worked out which one it was, but nothing's gone wrong after 20000 kilometres of driving with this mystery wire neatly cut and taped.