I thought we'd been through this. 2.0 can be upgraded (via a fileshared download) with a CD. 2.1 doesn't have full postcode functionality. 2.2 has full postcodes. The grey area is whether 2.1's can be upgraded to 2.2's.
Well, I have full postcode functionality on my 2.0, but if 2.1 uses a CD, that should be upgradeable too, unless there is some crackpot reason why not?
It is my understanding that the Seat Media System version, doesn't have anything to do with whether you have 7 digit postcodes or not, it's the maps that are used with your version that affect the postcodes. Seat Media System version 2.0, and 2.1 use a CD to update the maps (correct me if I'm wrong about 2.1), which where then written to an SD card (if you wanted). The latest Seat Media System (2.2) use an encrypted SD card to update to the latest maps.
So I would think that as long as you can download the latest map version, you can put them on any Seat Media System that can update via a CD. It just happens that the latest version numbers come with the latest maps.
The version numbers would refer to different functionality that the unit has. For instance, my 2.0 cannot show any phone information on the RNS screen, where as the latest 2.2 version can. There are probably hardware upgrades in there as well, I believe the latest 2.2 version has internal storage (I think these changes are because Seat Media System 2.0, and 2.1 are RNS-310 units, where as 2.2 is the RNS-315)
That's my take on it anyway, someone please correct me if I'm wrong
tl;dr I thought as long as you can use a CD to upgrade to the latest maps, it should be no
problem.
P.S I can tell you where to get the maps from, but I imagine I'm not allowed to post that on here.