See also:

The concept
This system projects important information into the driver's field of vision, e.g., the speed. In this way, the driver can get information without averting his or her eyes from the road. ...

Reference
This chapter contains technical data, short commands for the voice activation system, and an index that will quickly take you to the information you need. ...

Switching off automatically
The system switches off and the LED goes out: After approx. 160 ft/50 m when driving forward. Above approx. 22 mph/36 km/h when driving forward. Switch on the system again if necessary. ...