Hi Lee Wood - the std set up for Emyway is no UK postcode set-up (it takes first 4 digits simply because that is the same as French code!)The speed cameras are disabled on all cars by default - Citroen policy that they do not want to encourage speeding!!
As derisim says you can get single speed camera update for £6.99 or annual for £26.99 - it comes as a download you load onto USB drive and then plug into your car and follow upload instructions. I got just one update for June - as cameras don't change place that often these days (even mobile unit sites are pretty static) with cutbacks - so doing it every 4-6 months would be enough.
As for the postcode entry - you can enter GPS co-ordinates and the floowing link allows you to enter a postcode and get the co-ordinates to enter exact location into Emyway - it is the last GPS co-ordinates.