"HOLDEN ASSIST" is optional on the Calais. Combining mobile phone and global positioning system technology, the system puts drivers in direct phone contact with the Holden Assist Centre, which is manned 24 hours a day and offers a range of support services. The Holden Assist system can also remotely unlock doors on command, diagnose low battery voltage, detect unauthorised entry, track and immobilise the vehicle if stolen and automatically notify authorities of an airbag deployment.