Around 200 visitors gathered before the gates opened at 7am for Australia's largest swap meet.

Organiser Trevor Wolstenholme said around 25,000 visitors were expected to attend the three-day event.

He said 2500 trade stall holders were on site selling a huge range of items. From restored classic cars to rusty old bits of metal, Mr Wolstenholme said there was something for every car enthusiast.

"It's got a great atmosphere," he said. "And it's got something for all ages from the young up to people in their 70s - it's an event everyone can enjoy."

Even yesterday's unseasonally cool temperatures were not enough to discourage keen bargain hunters.

"A lot of people find bits they never thought they'd get," Mr Wolstenholme said.

But finding that elusive part could take patience and just a bit of luck - with bargains spread over 70 hectares, Mr Wolstenholme said it could take a couple of days to see everything.

Gabrielle Djordevic and partner Charlie Mangiafico spend six months a year selling goods at swap meets and field days.

Based in the Melbourne suburb of Wantirna, the couple looks forward to the Ballarat meet.

"We go from Rockhampton to Tassie and everywhere in between," Ms Djordevic said.

"We've been coming to Ballarat for about six years and we usually do fairly well."

The couple's stalls included car accessories, tow ropes and even jewellery. Ms Djordevic said her range of laser-etched Ford and Holden paperweights, rear vision mirror crystals and necklaces usually sold well.

"It gives the girls something to look at while the boys are out looking at all the toys."

Stallholders Neville Collison and Kelvin Murphy made the trip from Werribee, but admitted most of their goods were "junk".

"We come to make a dollar and clean out the shed at the same time," Mr Collison said.

The pair said they tried to resist the temptation of taking home more than they came with.

"I think I got a great bargain last year though," Mr Collison said.

"I bought brand new 4WD tyres for $100 each."

The swap meet will be open today until 8pm and tomorrow from 7am to midday. Entry is $10 per person per day, children under 12 are free.