Safety systems at a tarmac rally dubbed the world's most challenging were "questionable", an inquest into the deaths of four competitors has been told.
Leigh Mundy and his co-driver Dennis Neagle were killed on the final day of the 2021 Targa Tasmania event when their Porsche crashed south of Hobart.
A day earlier, Shane Navin from NSW died when he lost control of his 1979 Mazda RX-7 during a stage on the remote west coast.
In 2022, 59-year-old Queensland Tony Seymour was killed in a crash in the state's north west.
Targa Tasmania, which was scheduled to resume in April, has been postponed until 2025 so a host of reforms including training requirements for drivers can be implemented.
An inquest, which began in Hobart on Tuesday, was told the 1900km event had operated in wet and slippery conditions and at times without speed limits.
"Given the (limited) experience of drivers ... the risk of death was high," counsel assisting the coroner, Sara-Jane Knott, said in an opening statement.
She said Targa Tasmania and governing body Motorsport Australia had provided a large volume of evidence.
"(Some information) has raised questions about the systems in place for the operation of such a high-risk event," she said.
Glenn Evans, Mr Navin's co-driver, recalled their Mazda losing grip on the Mount Arrowsmith stage and ending up upside down, semi-submerged in a creek.
"Shane (said) 'I'm f*****', or 'oh s***'. (But) Shane caught the car and had the wheels running in dirt … brought (it) back onto the road," he said.
"As I looked down, my recollection is we were not quite straight … the next recollection was the front of the car dipped.
"What I clearly remember … (is) landing very heavily on its roof.
"I just remember a couple of seconds of disorientation. I called for Shane and got no response."
Mr Evans said he couldn't feel a pulse on Mr Navin and tried to get him out of the car but was unable to because of the "wings" on his friend's seat.
He scrambled up to the road to alert a passing competitor but realised the crashed car couldn't be seen by those driving past.
Mr Evans said he later found out the car's alert system hadn't gone off.
"We hadn't explicitly been advised that a rollover wouldn't automatically trigger an SOS," he said.
Mr Evans said race officials had warned the Mount Arrowsmith stage was "very slippery" from 33km onwards.
Targa Tasmania's safety procedures relied on a crash being visible, Mr Evans said, adding cars passed without knowing they were there.
An event course checker, Graham Malcolm, said he had noticed a bump on the road where the crash happened but it wasn't out of character.
The inquest will probe 16 issues, including the thoroughness of pre-race briefings and whether the crash alert system was compliant.
Ms Knott said not all recommendations made by a tribunal after the 2021 event were implemented by 2022, including independent assessment of car suitability.
Targa Australia's lawyer Dean Jordan anticipated the evidence would identify shortcomings and said the organisation was committed to implementing any inquest recommendations.
