Work in progress...

Currently I am busy with the suspension upgrade of the Volksback, but I want to get ready with the Streaker also, so I grabbed the airbox with 2-speed electric fan which I bought in Budel. It was filthy and covered in different shades of overspray, but fully functional!
After disassembly, I started with this:

The cover had traces of red, green and blue overspray - especially in the mesh...
After a  good clean it was much better:

So I started the assembly again

Carefully cleaned the fan (this thing is vulnerable!) and gave the motor a good clean + a bath in WD40, then assembled onto the inner housing:

inner housing completed:

Inner housing mounted to outer cover: 

and the finished box:

 ... with new fixation clips. Not show quality, but good enough for me!