Woo Hoo!
I can now use the A/C without the car sounding like a hovercraft.
Small fan has been replaced by MDM Technik in Berks and is now operational. Previously with the AC on you could see it wasn't moving if you popped the bonnet open. When it stops working, the larger radiator fan kicks in at a higher RPM, hence the noise.
Cost:
£127 +Vat for the fan, £55 +Vat for fitting.
There are 2 potential fans which could be used, one by Siemens, one by Temic. Neither fan is labelled as far as I could see even when removed. In the end MDM ordered both and matched it up by sight (one has more fan blades apparently). Part numbers are:
1K0 959 455 ET - Siemens
1K0 959 455 CR - Temic
Mines an 07 plate and I had the latter part by Temic.
Would recommend Mark at MDM if you need any work done. They're a REVO dealer as well, so I'll be back in the future,
Cheers,
Chris