Selector lever

P = Park position, wheels are locked; engage only when the vehicle is stationary and the parking brake is applied.
R = Reverse; engage only when the vehicle is stationary.
N = Neutral.
D = Automatic mode with all gears.
The selector lever is locked in P and can only be moved when the ignition is on and the brake pedal is depressed.

If the brake pedal is not depressed, the indicator
lights up.
If the selector lever is not in P when the ignition is switched off, the indicators
and P flash.
To engage the lever in P or R, press the release button.
The engine can only be started when the lever is in position P or N. When position N is selected, depress the brake pedal or apply the parking brake before starting.
Do not operate the accelerator pedal when changing gears. Never operate the accelerator pedal and brake pedal at the same time.
When a gear is selected, the vehicle moves off slowly when the brake is released.
Engine braking
To use the engine braking effect, downshift in time when driving downhill, see Manual mode.
Freeing the vehicle
Alternating between forward and reverse is only permitted if the vehicle is stuck in sand, mud or snow. Move the selector lever repeatedly between positions D and R. Do not race the engine and avoid sudden acceleration.
Parking
Apply the parking brake and move the lever to P.
The ignition key can only be removed when the selector lever is in position P.
Test yourself
A quick Opel Insignia quiz: every answer comes with an explanation and a link to the manual page.