I got my Bentley service manual for the VW Golf - albeit for 2002 (I couldn't find the 2003 edition on Amazon).

This is a lot easier to understand than the Haynes manual - partly because it's a lot bigger (over 1,000 pages), and also because it is mostly diagrams rather than pictures.

I had this bit left over - it was easy to see in the Bentley manual that it was the lower radiator drain valve.

I also made a note of the engine code - AUQ

This bit is the lower radiator exit pipe

This is the upper radiator exit pipe

This is one of the heater pipes

And this is the other

I thought this was the water pump, but it's actually a secondary air pump. The pipe that's missing goes to the air box, so I could simply replace it with a small air filter.

And these are pipes I don't know where they go. This is part of the air system. I think it connects with the charcoal filter.

These are air pipes

This little box was one of the unidentified parts; I think it's an air reservoir.

These pipes I identified earlier. They're the connections to the water header tank.

With everything labelled either with their purpose, or what they're holding (4 air pipes), I measured the ones I need to get the pipework for.

Unfortunately, the drain valve makes it point the wrong direction, so I can't use it.

I've arranged a workshop visit to see what's done on the demonstrator, and also another one they're building. I'll also discuss the intercooler arrangement.