Does anyone know what versions of which DVDs will work with the MMI Plus in a 55 plate 2.0TDI SE A6?

I am after up to date DVD maps. I bought a RNS-E DVD of the Internet but it does not work with my system.

Looking at the files on the DVDs the 2005 disk has a bunch of *.DB files and the RNS-E disk has a lot of *.IDX files.

What do I need to get without paying the dealership £200?