Sirius Radio Nav+4
BTW, I feel so so about this feature. The blue tooth is almost impossible to set up, and the AUG jack stopped working. The USB works like a champ, which was really why I purchased this feature. The navigation is ok, but I am unsure how to update it since it does not take DVD updates.
The UMI Nav+4 itself does not include Sirius. In most (all?) model years, Sirius was included in Package 1, which is a very common option so most W204s have Sirius, or available as a separate option.
To find out if you have Sirius, press the RADIO button on the dash multiple times to cycle through the radio bands. If Sirius comes up, you have it; if it doesn't, you don't have it.
Updates for the UMI are provided on a USB flash drive rather than DVD.



