Does Subaru NavTeq DVD use old and new Europe maps together?

[kevmac YTY]

Have a Nuvi 670 and Subaru built-in SatNav in car so I can easily compare map data quality – Nuvi has 100% Ireland mapping.

Have just got new Version 4 Subaru Europe DVD map which still does not have 100% mapping for Ireland – I am guessing that Subaru used Q4 2005 in their latest release (rip-off to charge customers for ancient map data).

Now I hear unofficially from Subaru that they have a deal with Navteq where they buy different country maps from different NavTeq data releases and piece them together themselves.

To be clear: Subaru gauge which countries in Europe they sell the most SatNav car units and apply the latest map data release to that country, for example UK and Germany – Ireland would have a small amount of sales so they buy older map data and save money.

Two questions: Do NavTeq allow this piecemeal assembly of different date maps of different countries to be assembled like this?

Does this logic then mess European travellers up if they are driving across the continent?

Thanks for any replies.