i've sucessfully upgraded my GM1200 and GP1200 to MT2100 Series. After that i spend some time with selection calls and now i think, i now how to use them

How does the group call works?
In the Woopie i can set a group call position with a "G" - My actual configruation is, that a direct call is done with "D3316" - "D" for "direct" and 3316 as my ID. The call for the next in range would be "D3317" and so on... ID's are from 2200 to 4401.
My understandig is, that the group call position to call all radios has to be set as "-G-----" ? But what do i have to set in the Adressbook to make a Group Call?
It would be great, if someone could give me the little short help to understand this feature

The other small questions are:
- is there a feature for car audio mute for this radios?
- I set the display to "A: xxxx S: xxxx" in the portable radio - is there any way to show the "decoder id" and "decoder status" in the display? f.e. with a function to switch display. Or how do you recieve status messages in this radios?
Thanx a lot for any replies.
Juergen