"My baby didn't have an absolute chance," his mother Sherry Tosh told the Herald.
"You could look at the pictures of that car and when you look at it you would think there are two cars there."
She let out "a scream and a wail...that just howls through your heart" when Bianca came home and broke the news, she said.
Sherry and her husband Fraser Tosh are now making a desperate plea for others to take care on our roads and to look after each other.
Morgan was a "cheeky monkey" with an incredibly big heart. His countless kind gestures for others were often little things - like walking a classmate between lessons because they were going through a hard time.
He was energetic, sporting, fun, passionate and stubborn - but his life was cut brutally short.
There were so many things that made a cruel and unnecessary tragedy so much worse, including who it had been witnessed by, Sherry said.
"He went with a good friend who now sadly has to live with this for his life," she said.
"It is just such a waste."
Sherry said her brother, who is a policeman, had shouldered some of the most horrendous and hurtful parts of what followed.
"It has broken him having to go to a car in the pouring rain in the dark and officially identify the body of his nephew."
This had affected so many people, she said, speaking of a ripple effect that had drawn masses to her boy's funeral.
"And it has to have meant something," she said.
"We should still have our boy. We should have had a family Christmas here."
The normal nagging about not being silly in the car was not getting through to young people, she said.
They needed to be able to take it somewhere safe, she said, asking that people leaving it on the track.
"He's not just a number, he's our son," Fraser said.
Often when he heard on the news a young person had died on the road he truly felt a deep sorrow for what that family is going through, he said.
But you never, ever, really imagine that it could happen to you, he said.
"He was a boy turning into a man and going through all the struggles that a teenage boy would go through," Fraser said.
Morgan could be relied on to look after others. Even back in primary school he stuck up for kids who were being bullied, he said.
"I always said to Morgan that I had his back, and unfortunately this time I didn't."
Sherry said they felt blessed to have had him in their lives.
"Sometimes you just don't realise that at the actual time. He was a cheeky little monkey and he didn't make everything absolutely easy for us as parents.
"He has done us proud in many ways actually."
He was a good brother to Bianca and their older sister Jolie.
His mother said with just 15 years to look back it was so easy to remember him as a baby with a twinkle in his eye who had been born at home, caught by the steady hands of his dad.
"I should have known even right from then that we were going to have a good ride with Morgan," Sherry said.
"This whole thing has changed our lives forever. Things will never be the same as they were before," Fraser said.