Facelifted W203 cars (2004-2007) were originally factory-fitted with NTG2 (when the COMAND option was ticked).
After W203 production stopped in 2007, the successor W204 was in fact only available as saloon and estate - while the contemporary C-Lass coupe - the CLC - was actually still based on the old W203 with modified front and rear ends.
The CLC got in 2009 (MY= Model Year) the NTG2.5 unit, and while this unit was never officially available with the older W203 cars of 2004-2007, because the CLC was in fact based on the W203 of old, the NTG2.5 made for the CLC can be retrofitted to facelifted W203 cars.