But in the car, he was in total control -- trying out a button that started playing music, opening and shutting the door, and tipping out a bag of accessories that he found on the floor.
"That was not like him to get in there and do that without me," Mrs King said. "It's really going to help Oliver's confidence."
Oliver and his older brother Ethan, 4, who has the same degenerative condition, today became the 75th and 76th Kiwi children to get electric cars specially adapted for each of them so they can become as mobile as other youngsters.
Jonathan Martin, a 4-year-old from Mt Albert with Down syndrome, struggles to sit up at home but became an instant driver in his new car.
"He can sit but it's not balanced," said his dad Romesh Martin. But he can put his foot down like a rally driver.
Professor Cole Galloway, a brain scientist who started the GoBabyGo charity in the United States in 2006, said moving around transformed a child's development and the way other people interacted with them.
"This kind of toy is cool, and cool brings other kids to you, so what happens? They socialise more, they communicate more, their cognitive skills get a little bit higher," he said.
"And the adults are watching. These cars don't say, 'My kid can't do something', which everyone has been saying to them. These guys say, 'This is cool'."
GoBabyGo's New Zealand chapter started in 2014 when motoring journalist Jacqui Madelin saw what Professor Galloway was doing on YouTube. She roped in others to serve on a trust. BMW pays for the cars and Auckland Z Energy franchisee Keith Murray has paid for materials to adapt them. No one is paid for their work.
Benjiro Fenwick checks out his new 'GoBabyGo' car at BMW. Photo / Greg Bowker
"I just rang a group of mates and said, 'Guess what, you're giving a hand to do it,"' said another trustee Mark Prujean, who sells Top Taste chicken and chips equipment and has been helping disabled people since he was diagnosed with Guillain-Barre Syndrome as a young man.
Mr Prujean often delivers the cars himself when he travels around the country for his business.
Chief executive Gilli Sinclair, whose day job is running an inter-country adoption agency, said the trust aimed to give a car to every mobility-impaired child in the country, and eventually in the Pacific Islands too.
"We think there would be maybe 1000 kids in New Zealand that we could offer cars for," she said.
"We have lots of cars and we are waiting for children. When we hear from kids who want it done, we go and do a build in that area."
