If you're even unable to describe the unit in your 204 C-Class how do you expect us to help you?
You could have the
- Navigation 20 UMI Update by dealer only
- Audio 50 APS NTG4 Mercedes Audio 50 APS NTG 4 (W204)
- Comand APS NTG4 http://gpsunderground.com/forum/merc...048277659.html