CAR companies have been refitting recalled vehicles with potentially deadly airbags that have killed at least 18 people around the world, including in Australia.

An investigation by consumer group Choice has found that Toyota, Mazda, BMW, Lexus and Subaru have admitted refitting some faulty Takata airbags with identical replacements, while other manufacturers had not shared information.

The airbag mechanism becomes faulty after the airbag has aged, with Toyota saying the replacement airbags would be safe for "a number of years".

Choice's report follows an incident where serious injuries were suffered by a Northern Territory woman in April, and the recent death of a New South Wales man after his Honda CR-V's airbag ruptured in a crash and he was hit in the neck by debris.

Japan's Takata Corporation last month filed for bankruptcy amid the world's largest ever automotive product recall, affecting 100 million vehicles globally including 2.3 million in Australia.

Choice spokesman Tom Godfrey said consumers needed to understand the severity of the problem, with many motorists effectively "driving around with an improvised explosive device a few centimetres from your face".

"It can fire shrapnel at you and your family," he said.

"The scale and severity of this recall is terrifying. It's clear that these car companies are under a great deal of pressure … it's unfortunate that many people who contact them can't get a remedy within a reasonable period of time."

Choice is concerned that some car owners were told by dealers to wait more than six months for a repair. It said several car companies had refitted some recalled vehicles with like-for-like Takata airbags.

Australian Competition and Consumer Commission chairman Rod Sims said there had been problems sourcing stock and suppliers given the scale of the airbag recall across 60 makes of cars sold in Australia. Car makers now had enough stock available, he said.

HOW CHOICE TELLS THIS STORY

It was the airbag that left the 21-year-old Australian hospitalised in serious condition.

It happened early on a Monday morning in April. Forecasts say the weather was a fine 25 degrees. She was driving down McMillans Road in Darwin when a car pulled out suddenly.

At 8.11am, there was impact. Her airbag deployed within 0.05 of a second. Were it a different airbag, made by a company not involved in decade-long cover up, she would've been okay, but the airbag went off explosively and a shard of metal shot at her face.

"This type of crash, in normal circumstances, would not have caused this level of injury," says Sergeant Mark Casey of the NT Major Crash Investigation Unit.

The unnamed 21-year-old was the first Australian to fall victim to the largest recall in automotive history, but the laws of probability indicate she will not be the last.

A hundred million vehicles are affected worldwide by the recall of Takata airbags. More than 180 people have sustained injuries as severe as blinding, paralysis and severed vocal chords. To date the global death count stands at 18.

The recall of Takata airbags in Australia is 21 times bigger than that of Volkswagen's emission tampering scandal, and yet - even though it has led to injuries and fatalities - there's little awareness, little outrage.

Thirteen manufacturers have these airbags fitted in over fifty models of cars, with prices as varied as a $15,000 Honda Jazz to a $526,000 Ferrari 458. Manufacturers doubt they'll get close to replacing all of the cars affected.

More at Choice