The W204 2004 to 2011 uses NTG4
The GL up to 8/2008 uses NTG2 which is the same as C class update from 04 to 07
The part number of the 2012 NTG2 Aus/NZ maps is A169 827 53 59.
Download "3_mercedes.pdf"
from this site
[Please Register or Login to download file] This pdf shows the discs required for all models.
The DVD box for the W203 update model has a light blue stripe A169 827 xx 59
The DVD box for the W204 up to 2012 has a violet stripe A204 827 xx 59
Hopes this helps