Stereo "upgrade" from previous owner, need help with wiring colours

[stutter]

Hey guys.

Previous owner of my '07 9n3 did a stereo "upgrade". The main loom connector is still in the dash, but the majority of the wire ends and smaller connectors have been cut and tossed. It's an absolute nightmare in there, and I'm shocked that the dash hasn't self-immolated yet.
The replacement stereo they went for was some £25 Chinese thing. I'm putting a *slightly* more expensive Chinese thing in as a stopgap until I buy something proper.
Anyone have the wire colour codes for what's what in there? It honestly looks like someone took a dull steak knife to the wires. Everything is just twisted together and wrapped with an inch of electric tape.....

[Maarten]

I: Speakers (brown block)
1 right rear+ blue
2 right front + ---red
3 left front + ---green
4 left rear + ---white
5 right rear - ---brown/blue
6 right front - ---brown/red
7 left front - ---brown/green
8 left rear - --- brown/white

II: (black block)
9 CAN + ---Orange/black
10 CAN - ---Orange/brown
11 Lights ---grey/blue
12 Kl. 31 Earth ---Brown
13 Radio on signal + (ACC +) ---Black/red
14 not pinned
15 Kl. 30 live 12v + ---Red/yellow
16 Signal SAFE anti theft ---Red/yellow

If you only have front speakers then there will be no wires for the rear speakers.
Then pins 1 + 4 + 5 + 8 will be empty

[stutter]

I: Speakers (brown block)
1 right rear+ blue
2 right front + ---red
3 left front + ---green
4 left rear + ---white
5 right rear - ---brown/blue
6 right front - ---brown/red
7 left front - ---brown/green
8 left rear - --- brown/white

II: (black block)
9 CAN + ---Orange/black
10 CAN - ---Orange/brown
11 Lights ---grey/blue
12 Kl. 31 Earth ---Brown
13 Radio on signal + (ACC +) ---Black/red
14 not pinned
15 Kl. 30 live 12v + ---Red/yellow
16 Signal SAFE anti theft ---Red/yellow

If you only have front speakers then there will be no wires for the rear speakers.
Then pins 1 + 4 + 5 + 8 will be empty

Absolute legend