Before leaving the vehicle, fully press the clutch pedal down, move the shift lever into R (Reverse), and firmly apply the parking brake. Once the shift lever has been placed in R (Reverse) with the clutch pedal pressed down, the ignition key can be turned to LOCK/OFF, then remove the key and release the clutch pedal.
See Manual Transmission Operation.
Shifting Out of Park (Automatic Transmission)
Parking Over Things That BurnChevrolet Cobalt Owners Manual. Keys
WARNING:
Leaving children in a vehicle with the ignition key
is dangerous for many reasons, children or others
could be badly injured or even killed. They could
operate the power windows or other controls or
even make the vehicle move. The windows will
function with the keys in the ignition an ...