Update June 2016
With the hotter summer months I've now started back using AC. Noticed it wasn't working well so I VCDS scanned and found the error code P00819 relating to a failed G65 sensor - Part Number 1K0-959-126-A
To change this sensor isn't much work at all if you have a 17mm crows foot spanner and suitable extension bar:
The sensor is at the front of the engine facing just slightly below the alternator
A quick change of this and a gas top up then I'm good to go.