He did not know if the deceased was a man or woman.
Police would not release details of the victim until next of kin had been notified and the Counties Manukau Serious Crash unit was now investigating.
A resident on the 50km/h street said her grandchildren heard a loud bang.
The woman, who did not want to be named, said she saw a man outside the car shortly after.
"He was just a young guy. I saw him before the ambulance arrive and he was yelling and wailing... terrible."
She said the car was travelling into the direction of the sun.
"I would say he's had sun strike."
The sun was so bright in the mornings she said her family closed drapes in their front room because it was "too blinding".
"And that's the way he was facing. It's just very sad."
The front of the sedan car went under the trailer of the truck, which the woman had never seen parked in the suburban street before.
"It takes up nearly the whole lane."
She said police were still at the scene but the road was now open.
Shortly after at 8.05am a second crash occurred on Alfriston-Ardmore Rds when a car hit a power pole.
Fire and police attended and traffic was diverted for around 30 minutes, but has now cleared and roads are open.
Police said there were no injuries.
