What happens when someone steals your car? Or you forget the keys? Worst of all, what happens when you have a serious car accident?

For most of us, that last reality has thankfully never eventuated so the thought of consequent actions has been unnecessary. Sure, we probably assume or hope that passers-by will call an ambulance if we are unable to, and we also hope that emergency services can find us quickly.

That is a scenario no driver ever wants to find themselves in, but in case you do, Holden will soon have a system that will be right there to help, and you won’t even have to press a button.

It’s called OnStar and it has been evolving and saving lives for over two decades.

From 2019, Holden will introduce the OnStar system in its cars, and to find out what all the fuss is about, we came to Detroit, in Michigan, the home of the American automobile, to give the system a good go.

Firstly, this isn’t something new. It was first started all the way back in 1996 and over time it has evolved massively, with the 11th-generation of the hardware and software unit set to make its debut in what will launch locally with the Holden Equinox and other models from 2019.

So what is OnStar? To make a really long answer short, it’s basically a black box with an LTE 4G connection that lives inside your car. It allows you to call and talk to an actual human being in times of need, and even in times of wanting to find the best pizza joint nearby or directions to a place that you just cannot find.

It’s fully integrated with your vehicle’s electronics and drivetrain, allowing it to not only be tracked in case of theft, but also remotely stopped and disabled. Forgot your keys? No problems, it can automatically unlock and lock your car. Really hot day? No problems, it can automatically start your car and air conditioning remotely. Driving and can’t use the sat nav? No problem, call and talk to an actual human being who will send navigation data for your requested location over the air to your car!

Sounds too good to be true? Well, it’s already in operation, and as we found out, it works rather well.

Our first introduction to OnStar was to see the call centre in Detroit. In the U.S. alone, there are over 2500 call centre staff, and they take a call every three seconds and deal with an average of 245,000 calls per day. The command centre looks like something straight out of Hollywood, with red dots over a map of USA that show hot spots and crisis areas. It's fascinating to watch.

In the States, around 5000 calls a month are automatic crash response notifications, which sees the vehicle dial OnStar immediately post an airbag deployment. These calls are usually answered in less than five seconds by OnCall staff.

The director of OnStar global expansion, Jon Hyde, told us automatic crash response calls are usually dialed and answered while the vehicle is still moving post-accident, and on many occasions, it’s when the vehicle may still be rolling down a hill. That’s how quick the system calls for help.

The idea is simple, once an airbag goes off, the vehicle immediately calls for help. It provides a great deal of data to the OnStar staff which helps them determine the severity of the accident. This includes the vehicle speed at time of impact, which airbags have been deployed and on which side, the age and sex of the owner of the vehicle (older females most likely to be injured in an accident) and so on.

For example, in Australia, if a Holden automatically dials for help and passes on the information that the airbag was deployed on the right-hand side of the vehicle, both front and side airbags, and at a relatively high impact speed, it’s fair for the OnStar staff to assume the driver may be injured or unconscious.

Immediate attempts are made to communicate with the occupants of the vehicle to assess the situation. If no communication is possible, emergency services are called in urgently with the exact pinpoint location of the vehicle down to a GPS level of around one-metre accuracy.

OnStar staff remain on the phone until emergency services arrive; in fact, they can go as far as to flash the lights and sound the horn to allow an ambulance to find the vehicle in poor lighting conditions (such as a vehicle having rolled down a hill at night).

If occupants are able to communicate, an emergency-level procedure is undertaken to assess the situation. This includes asking who is injured, if anyone is trapped, et cetera. General Motors says it has taken all the learnings from 911 call centres in how to help and assess these types of post-accident situations.

The way it works is that the first OnStar staff begins the process of determining whether or not the situation requires an ambulance. If that is the case, a second OnStar staff member will take the job of calling emergency services and informing them of the impact situation, the vehicle's location and the occupants inside the vehicle, all the while the first OnStar staff remains on the phone to the occupants providing emergency care and over-the-phone triage.

We were shown and allowed to listen to half-a-dozen examples of where the OnStar automatic crash response system had saved the lives of those in need. In one example, an elderly grandmother and her granddaughter had been in a vehicle that had left the road and found itself submerged upside down in water and quickly sinking very late at night on a dark road.

The OnStar staff were able to quickly provide the vehicle’s exact location, while also flashing the lights and blowing the horn remotely, allowing the ambulance to find the sinking vehicle far quicker than before, with every second being vital in a situation like that.

Another interesting feature of OnStar is the crisis management system. For example, in a Queensland flood or Victorian bushfire, OnStar staff are able to help those stuck or trapped in their vehicle, by not only providing a location to emergency services, but also allowing others to avoid the same route.

General Motors used recent examples of hurricanes in Texas, in which many OnStar enabled vehicles were calling in for help to find a way out of affected areas, and also to locate a working fuel station. OnStar worked immediately with MasterCard, which provided data for nearby locations where credit cards were used at petrol stations, and that helped OnStar staff determine potentially functioning stations to send customers to. All of these things happened in real time as part of OnStar’s crisis management system.

Moving down the list of its capabilities, perhaps the next most useful feature of OnStar is the ability to basically theft-proof the vehicle.

If an OnStar enabled vehicle is stolen, its owner simply has to call Holden, which will immediately put an ignition lock on the vehicle. This means the next time the vehicle is turned off, it can no longer be turned back on. It will then liaise with local police to locate the vehicle.

Going one step further, if the vehicle is stolen, then continuously driven (say as part of a criminal activity or high-speed chase), OnStar has the ability to remotely disable the vehicle’s accelerator. In the U.S. this is done only once a police vehicle or helicopter has a visual on the car to determine that it is safe to do so. OnStar forces the vehicle's hazard lights to turn on (without showing any indication of doing so on the instrument cluster) so that police can identify the vehicle correctly and also to warn other motorists of its impending slowdown.

As part of a demo, we headed out on the streets of Detroit and did our best criminal impersonation. While making our getaway with Eminem blasting on the stereo, OnStar staff were able to remotely disable the right pedal, which meant that all we could do was come to halt. We got out and made a run for it. OnStar also has the ability to remotely lock the vehicle but has chosen not to in case there is a hostage situation or other unforeseen innocent parties involved.

According to provided data, more than 99 per cent of stolen vehicles with OnStar are recovered within a short period of time, making them all but theft-proof.

Those are the main and perhaps most useful features of OnStar. Its ability to automatically call for help and enable pinpoint accuracy of the vehicle cannot be underestimated in post serious crash situations, it can and has shown to be the difference between a fatality and a life saved.

There are three buttons for OnStar; the system usually resides on the rear-view mirror. The red button is for emergency situations, the blue button is when you just need help with either navigation or otherwise and the white button is to allow you to go incognito, disabling the vehicle being tracked incase you value your privacy (nonetheless, if there is an airbag deployment, it will renable location services automatically).

Plenty of OnStar customers also use the system to call help for others they see having had an accident on the road. Even if the other vehicles are not OnStar enabled, the accident report finds its way with the location immediately to emergency services.

The system requires phone reception, however, unlike your smartphone, the OnStar system has a rather noticeable and large antenna on the roof, which allows it to have better phone reception than you’d get from your iPhone. General Motors allowed us to listen to an example of a husband and father frantically using OnStar staff to contact his wife and kids who had been stuck in their vehicle in a disaster zone, with all their phones having no reception, but OnStar managing to get through with a stronger signal.

But it’s not all that serious. It can also be rather fun to use, for example, after being let go with a warning post our heist, we used the blue button to find directions to our hotel. We then also asked for a recommendation for a good Pizza place on the way to the hotel.

OnStar staff were able to remotely send turn by turn navigation data straight to the car, which meant there was no annoying programming required using the car’s infotainment system. We literally pressed just one button. Strangely, the navigation system is purely turn by turn indications, without a map. Which we found odd.

Having pressed the blue button we waited, perhaps 25 seconds for a response, which is not all that bad. The red button gets far more priority for obvious reasons.

Perhaps the most gimmicky and commercial part of OnStar is the iPhone and Android app, which will be called MyHolden in Australia. This allows the owner to unlock and lock their vehicle remotely, also to start and turn off the engine just using their phone.

It also means direct access to the vehicle’s health, so you can see how your oil level is going or tyre pressures and brake pads. It also allows you to book a service and pass on the data of your car’s needs to the dealer for a better service experience, making sure the necessary parts are in stock before you come in, all seamlessly, without ever having to actually talk to a service manager.

The app will also inform you of any recalls or other service actions that may be outstanding on your vehicle.

Another feature that most families will love is OnStar’s ability to provide a 4G LTE hotspot in the vehicle for the kids. Using the same SIM and modem that powers the rest of the system, OnStar sets up a Wi-Fi connection inside the car that iPads will love for Netflix streaming.

In all respects, OnStar is fantastic for its safety benefits alone; the addition of its other features is a bonus, but one which you will pay more for. Oh yes, did we forget to mention? It’s not free.

Actually, the fact that the basic safety system isn’t free is disappointing. It’s hard to fathom that an OnStar-equipped Holden that hasn’t paid to subscribe to the service can be in a serious car accident and not have its system active as to call for help, allowing its occupants to needlessly suffer, just for the sake of a small monthly fee. But business is business and with over 13 million active users, OnStar is good business for General Motors.

Given the launch of the system is still more than a year away, the fees are so far undetermined for our market, however, in other markets they start at around $25 a month for the basic safety system and anti-theft protection, and go up to around $45-$50 for the full whizzbang of features including in-car Wi-Fi.

Is it worth it? We think you’d be mad not to have the basic safety feature enabled just in case you ever need it. Also, Holden will provide a few months free trial with every new car and depending on how good your negotiation skills may be, it's likely you can get it thrown in for an extended period of time when purchasing.

We look forward to testing the system locally when it arrives with the Holden Equinox in 2019, but for now, it makes us wonder why every car manufacturer doesn't offer a similar system?