See also:

Mercedes-Benz M-Class Owners Manual
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Making adjustments in 1 mph (Canada: 1 km/h) increments
Briefly press the cruise control lever to the pressure point, up 1 for a higher speed or down 2 for a lower speed. The last speed stored is increased or reduced. ...

Opening the hood
WARNING Do not pull the release lever while the vehicle is in motion. Otherwise, the hood could be forced open by passing air flow. This could cause the hood to come loose and injure you and ...