Switching the microphone to mute
When a call is active, the microphone can be muted.
1. "Telephone".
2. "Active calls".
3. 
"Microphone mute"
A microphone that has been switched to mute is automatically reactivated:
▷ When a new connection is established.
▷ When switching between call parties.
See also:
Malfunction
In the event of a failure or malfunction of the
parking brake, secure the vehicle against rolling
using a wheel chock, for example, when leaving
it. ...
Switch off the engine during longer
stops
Switch off the engine during longer stops, e.g.,
at traffic lights, railroad crossings or in traffic
congestion.
Fuel savings are achieved after the vehicle is
switched off for only approx. 4 s ...
Close the windows and glass sunroof
Driving with the glass sunroof and windows
open results in increased air resistance and
raises fuel consumption. ...