"There's a few cars around that $5,000 - $6,000 mark so they can choose one that suits their needs best.
"It was the time of year, having kids ourselves, I just really felt sorry for them and wanted to do the right thing - more from father to father, not as a business person.
"I just wanted to make their lives a bit easier."
Daniel was diagnosed with cancer three days before Christmas, and was immediately transferred to Christchurch.
While the Williamsons were away, thieves stole their car from outside their Alicetown home. The next night, their house was burgled.
Incensed by the callous crimes, Mr Williamson contacted ZM radio DJ Polly Gillespie via Facebook to see if anyone knew who the "scum bags" were.
Gillespie, who has 85,138 likes on her Facebook page, shared the message and Mr Thompson soon got in touch.
"Almost instantly I got a message from Nigel Thompson, saying he'd like to give these people a car," she said.
"He didn't ask for any publicity, he just wanted to do it, as a father of young kids himself, I guess. To act on that instinct is just so lovely.
"I couldn't believe it. You know how often you read something, and go, 'That's so sad.' Well, he read it and went, 'That's so sad - but I can do something about that'. I thought that was so cool."
The Williamsons are expected to choose a car of their choice today.
When Mr Thompson returns from his Christmas holiday, he hopes to meet them in person.
"It's nice to do something that can make directly help someone. It's the least I could do," he said.
