Voice 1: Adrenaline just took over and instead of thinking what I should do I just put my foot down and accelerated and drove straight through all the orange flame.

Voice 2: It was pitch dark and headlights didn't do anything because of the smoke.

Voice 3: Every fibre was just screaming 'you've got to get out of here, the fire's coming'.

Voice 4: I warned my son a bit after seven o'clock that night not to come through. He said "I'll make it".

Mark Horstman: This is the last place you'd want to be in a bushfire... inside a car.

Narration: Cars and bushfires are a lethal combination.

Ash Wednesday, 1983...31 of the 46 fatalities were in or near vehicles.

Eyre Peninsula in South Australia, 2005. Tragically, nine people died. Eight of them were in or near their cars.

Mark Horstman: If you find yourself trapped inside a car in a bushfire what can you do to increase your chances of survival?

Narration: Andrew Sargeant from the CSIRO has been reading more coroners' reports about bushfires than he'd like.

Andrew Sargeant: It's literally an inferno. You would be getting exposed to probably about 80 times the radiant heat compared to a sunny day like this.

Andrew Sargeant: It must be horrific. Outside of the car it would be very dark, it would feel like it was raining fire. It would be very windy, the car would be moving a lot. Smoke would be unbearable, temperatures would be unbearable, you'd feel plastics melting away onto your skin.

Narration: Andrew's part of a team led by Justin Leonard that for the first time is putting cars to the test.

Their giant gas griller simulates the radiant heat of a real bushfire.

Justin Leonard: We've configured here a series of burners that actually run on liquid phase LPG and have designed the nozzles in a way that they project the gas up and it burns in a very similar way to an actual bushfire.

Narration: They spend hours in each test car fitting what looks like a tangled mess of wires.

Andrew Sargeant: And if we put another one there, it should hold the guide wires in place, no worries...

Justin Leonard: Surprisingly it's a highly organised set of sensors, where we bring temperature signals in from all different parts of the car.

Narration: All the data are beamed live to the scientists out of a fireproof box. From the ceiling to the floor, fifty sensors will paint a detailed heat map of the car.

But heat and radiation aren't the only challenges. A melting car makes plenty of smoke and toxic gases.

Dr Steve Brown: We have one point up here at the breathing zone of the driver, and at the same time we'll sample a second point down near the floor level.

Narration: Steve Brown sets up an air sampler to see what you'd be breathing if you were crouched down under a woollen blanket, as recommended by fire safety authorities.

Dr Steve Brown: A lot of car lining materials are PVC, and PVC when it's heated, even before it starts to ignite, will release hydrogen chloride gas, and that's a very severe irritant. Our aim is to see whether people will reach a point in the car where they feel too distressed and they panic and jump out.

Narration: Add to that a rising panic that the fuel tank may be about to explode. But after many tests, this hasn't happened once.

Justin Leonard: This test we're going to do a side-on exposure, and we're going to do it with the engine running and the air conditioning on.

Mark Horstman: Have you done this one before?

Justin Leonard: No. This is our first one with air conditioning so we're really interested in how much difference it really makes.

Andrew Sargeant: Ignition.

Narration: The radiant heat from the gas jets is building gradually, just like an approaching bushfire.

Justin Leonard: 4, 3, 2, 1, ten kilowatts.

Narration: Eight minutes into the test, and we're seeing the first signs of the car overheating.

Andrew Sargeant: See all the rubber, its all starting to drip down...

Justin Leonard: 2, 1, 20 kilowatts...

Narration: It's when you see it melt that you realise how much plastic and rubber there is.

Eleven minutes in, and the simulated fire-front is rolling over the car. It's peaking just above forty kilowatts, that's twenty times the pain threshold.

The exposed side bursts into flame.

Justin Leonard: Ignition of the car...

Narration: Twelve minutes in (bang) and there goes the front tyre.

Justin Leonard: Coming down to 20 kilowatts...

Narration: As the fire recedes it looks like there's smoke billowing inside the cabin.

Justin Leonard: End of test. Suppression crews...

Narration: The firemen start the water pump to save the instruments.

As soon as it's safe, Steve Brown is sucking out samples of the cabin smoke.

Dr Steve Brown: We've had about 200 parts per million of hydrogen chloride. That would be extremely irritating to somebody. I believe they'd want to get out of that car.

Andrew Sargeant: The interior for the most is still intact.

Justin Leonard: Just a small burn hole in the back seat.

Justin Leonard: Well that was probably one of the most revealing tests we've had. We learnt a lot about engine operation and how the aircon performed.

Narration: Although the windows stopped 70 percent of the radiant heat getting through, the range of temperatures inside is astonishing.

Justin Leonard: We've actually got peaks up around, as high as 250 in fact, very high in the cabin, but if you're down low under the blanket there very tenable around 40 to 50 degrees, which is quite survivable.

Narration: On the floor under the woollen blanket, you'd be able to survive the heat. But it's the toxic gases that could be lethal.

Justin Leonard: The preliminary results seem to indicate that it's a much cooler environment for the people to be in. However it looks like the stirring up effect of the air conditioning may in fact mix the toxic gases around in the cabin and may in fact be worse for the occupants.

Mark Horstman: The best advice is don't get caught in your car in the first place. Make your decision early enough to stay or go. But sometimes that's just not possible.

If you do get stuck, here's what you do: Shut the doors, shut all the windows. Turn your headlights on so people can see you. Close all the air vents.

Narration: Crouching down low and covering yourself with a woollen blanket really makes a difference.

And these tests show that lining up the car in a clearing front-on to the fire, and turning off the aircon and fan will also help.

Hopefully its information you'll never need, but in a land of bushfires, you never know.