The contingent of 200 cars, each worth less than $1000 each, has begun the impressive 3700 kilometre journey from Canberra to Townsville to raise money for the Cancer Council Australia.

The Shitbox Rally was the brainchild of James Freeman, who lost both of his parents to cancer within the space of the year.

Now in its sixth year, the event is the biggest independent fundraiser for the Cancer Council.

"So far it has collectively raised in excess of $5.8 million for cancer research and this year we've raised more than $1.2 million," Mr Freeman said.

"Pretty much everyone here has a cancer story similar to mine so it is great that people are able to focus that horribleness into something so productive and really quite therapeutic."

The annual event is not a race but there is still plenty of competition when it comes to decorating and naming a Shitbox ride.

One crew dressed in Canadian Mounted Police uniform piled into "The Mighty Moose", which was parked a stone's throw away from a canary yellow Kombi called "Wolf Creek Taxi Co" and "MC Badger", an entirely fur covered Jaguar.

Tom and Peter Corra, cousins from Watson, made up one of the 13 Canberra crews registered in the rally.

Despite the risks that cheap cars would break down, particularly on unsealed stretches in the north, Tom said he was quietly confident their old Volvo "Captain Krunch and the Cereal Killers" would go the distance.

"We've seen a few of the other rigs out there and we are quietly confident ours will get there," he said.

"Really it's a luxury model; it's even got power steering."

Peter will celebrate his 31st birthday during the rally but the pair planned to fly back to Canberra as Tom's wife was expecting a baby within weeks.

Life-long mates from Perth, Matt Burwood and Marty Sibley, drove for six days across the Nullarbor Plain to reach Canberra in their Daewoo Lanos covered in tennis balls.

"This is the second car on the list of cars not to take on the rally," Mr Burwood said.

"We named it 'The Gunna, as in 'we're gunna make it'."

Proudly wearing matching tennis gear, the duo said they hoped the car would be picked up at auction by a Townsville tennis club.

Canowindra father and son crew Brinn and Danny Jackett said when they're clapping along in the 1978 Volkswagon Golf "Jack it", they'll be thinking how much good will come from the generous donations from their small community - and the $2000 donation from The Green Shed in Canberra.

"We have raised nearly $6000," he said.

"There is such a great spirit in the rally. It's a great adventure for us but cancer touches everyone so we're just out there like everyone else to do some good."