ASTRA'S security system features remote central locking controlling doors, boot and fuel filler. When deadlocked, interior door handles and locks cannot be operated without a key, resisting entry by a third party. An engine immobiliser activates when the key is removed from the ignition. Lock cylinders in the driver's door and ignition are designed to "freewheel" if anything other than the correct key is inserted. An individual PIN number assists sound system security. Astra's engine is immediately disabled electronically when the key is removed from the ignition, immobilising the vehicle. An electronic PIN-controlled sound system helps discourage theft