See also:

Automatic deactivation during forward travel
The system switches off when a certain driving distance or speed is exceeded. Switch the system back on if necessary. ...

System limits
Speed range Best results are achieved when using the system on well-developed roads and highways. The desired speed can be selected between 20 mph/30 km/h to 110 mph/180 km/h. The system can al ...

Safety
Both the coupe and convertible have front airbags plus side-impact airbags built into the front seats. As required of all 2012 models sold in the U.S., the 640i has standard antilock brakes and an ...