It was also lucky the car's passenger side had borne the brunt of the collision, he said.
"All that huge amount of energy has been diverted down that side away from her... it would be fair to say that the amount of damage is disproportionate to the fact that she's is still alive."
The car was equipped with ABS brakes and airbags, all of which had helped to improve the "survivability" at the scene, Mr Megaw said.
"It's a really modern vehicle and the message is to try and get the most modern vehicle you can, especially if you're buying for kids."
People should try to buy the best car they could afford, he added.
When he arrived at the scene on Monday, he had been expecting the worst, Mr Megaw said.
"With that degree of damage and for someone to survive to this stage is extraordinary."
"This is as bad as it gets."
It was too soon to say what had caused Mrs Hoar's car to cross the centreline, Mr Megaw said, although it was possible fatigue had been an issue.
"Fatigue sneaks up on you really quickly and drivers should just take a break."
Mr Megaw said he wanted to thank all of the 60 or so people who had helped at the crash, from the firefighters who cut Mrs Hoar free from her car, to the witnesses and helicopter staff.
"A lot of people were directly involved, not counting the medical personnel and that doesn't include all the next of kin... so many people were involved."