The envelope left inside the second-hand car Jen Willis bought.

A single mum from Victoria says she was "blown away" by a kind surprise left for her in a second-hand car she bought.

Jen Willis, from Daylesford, purchased the Subaru Outback last Friday after seeing an ad online.

Ms Willis told she needed to buy a car quickly and had been recently going through a tough time, having just separated from her husband.

"I live with MS (multiple sclerosis) and I work full-time. My husband had just flown out to the US the week before and suddenly I am here with my two children and my son had been really sick," she said.

When Ms Willis called up about the car, the owner told her someone had already asked to come and inspect it.

Desperate to secure it, Ms Willis said she offered to give the owner a deposit without even seeing it.

"I had told the owner a bit about my story and I had a good feeling about him and the car. I thought he was a good person and I just had to trust my instincts," she said.

Ms Willis, pictured with her son Tyler, says the kind gesture took her by surprise.

The pair struck a deal and arranged to meet to complete the sale.

After the paperwork was signed, Ms Willis said she hopped in the car with her son.

"I went to drive off and I pulled the sun visor down and an envelope fell out," she said.

"I thought he had accidentally left it in there and then I read what was written on it."

"This is a random act of kindness," the note on the envelope read.

"Please use to spoil your family in a way that makes you happy."

The note went on to say the owner had felt in his heart that he wanted to help her during a "challenging time".

Inside the envelope there were three $50 notes.

"I teared up instantly and I was just blown away. It was completely unexpected. I had no idea," Ms Willis said.

Ms Willis shared the story in a post on the Kindness Pandemic's Facebook page, and it has since attracted more than 9000 reactions.

She said she had already decided how to use the gift.

"I'm going to take that money and the boys and I are going to go out and have a really nice dinner together," she said.

Contact reporter Emily McPherson at

Source: 9News