At the house yesterday morning children's bikes and toys could be seen in the front yard, next to the garden hose initially used to try to extinguish the fire.
The Holden's burnt-out shell remained in the driveway, next to a half-melted trampoline. No one was home.
Another car, parked less than a metre away, showed signs of extreme heat damage, with areas of paint work bubbled and melted.
Te Puke volunteer fire brigade member Glenn Williams said the man had been underneath the car working on it when it is believed petrol vapours ignited, causing the explosion.
The man, despite his burns, found a garden hose and began to try to put the fire out to prevent any of the three cars parked nearby catching alight. "But then someone from inside got him and put in him the shower for the burns."
Mr Williams said he understood there were young children in the house at the time but they were removed as firefighters worked to extinguish the fire and protect the house which was a metre away from the car.
The car was engulfed in flames when the brigade arrived, Mr Williams said.
The man was taken to Tauranga Hospital by ambulance before being airlifted to Waikato by the Westpac Waikato Air Ambulance.
Helicopter pilot Loren Haisley said the man suffered second degree burns to this face and hands.
"The nature of his burns weren't really that deep but they covered about 30 per cent of his body.
"The concerning thing with facial burns is that you can inhale [the flames] down your Nasal passages and your oesophagus and it can burn your lungs. That's usually a concern with these types of burns."
At the Te Puke property, neighbour Gael Mason said she woke to sirens and heard a loud bang.
"I thought there had been a crash, you don't really think of cars and explosions," she said.
Ms Mason said she believed the man was a grandfather.
He was the father of a younger man at the house, who had young children, she said.
When Ms Mason saw a fire truck in the driveway, with police and ambulance staff, she thought the neighbour's sleepout had caught fire.
She was surprised to learn it was the car, despite the man "always working in the car at odd hours".