Ok, I've got the factory sat nav and seem to have been very lucky in getting the iTMC enabled disc with it.

Works a treat, but I have one question. How do you enter a postcode as a destination?

Choose Destination, followed by Street Name.

When it display the street name, select the first letter of the Postcode then the the next 4

Unfortunatly it will only allow you to imput the first 5 characters.

After which you will be able to input the street name and number.

Thanks.. the user guide wasn't overly helpful!