"I'd never heard of it before and when I went to their Facebook page and googled I found their story was very touching.
"After you have had kids your heart goes out to anyone who loses theirs and I really do believe in passing on kindness," Mrs Armer said.
She had talked to her son, Fletch, about what had happened to Carson because she believed it was important to teach compassion and empathy.
"We have five cars that we want to hide throughout Rotorua. It doesn't say you have to pass it on but if you don't it defeats the point."
Fletch and his mum hid one of their five cars in the playground by the Rotorua Museum on Sunday.
"We are trying to remind people Carson died and that he was a nice boy," Fletch said.
Later that day 3-year-old Jah-ven Ashby Te Ohaere and his mum Larissa Ashby found the car. "It's so cool that my boy is a part of this," she said.
Carson's mum told the Rotorua Daily Post she was "blown away" the cars had travelled all the way to New Zealand.
"We never imagined these cars would go worldwide! We thought they would mainly stay in the States where our family and friends hide them, but those who have found the cars have felt moved and joined the effort!"
She said they had a map at home where they marked the locations the cars are placed.
"This project has been more healing than I ever thought possible. Every day it gives me something to do to feel like I am still taking care of Carson.
"Also, I think he would want us to continue trying to spread the joy that he freely gave when he was here so to hear the amazing stories of people who find these cars and how it touches their hearts, it makes me feel like I am working with Carson to spread his joy and that makes me happy."
How to get involved:
* Go to www.facebook.com/CarsonDeanCheney/
* Search #carsoncouragecars