In a winner's pavilion some 250 metres from the main burnout pit, Jim Soultas from Melbourne's northern suburbs couldn't hide his winning smile.

The Summernats veteran from Lalor in Melbourne's northern suburbs was more than happy to display his best in show trophies including his latest accolade – best sound system.

"Summernats is definitely not all about the burnouts and horsepower," he said. "We're not all hoons and there are people who are here to share their spoils and show everyone what sound quality is about.

"Obviously, you see the nice cars about the place but it's more of a social event. You come for the people"

Mr Soultas, who drives his winning vehicle every day as a commercial real estate agent, said his stereo system sounded best with "a bit of doof-doof or top-40".

"I purchased the car about 12 years ago for $70,000 and I've put in another $50-80,000 worth of work, so it is worth quite a lot now," he said.

Standing next to Mr Soultas was Michael Garcia, who also travelled from Melbourne with his specialised vehicle that won the best ute or pick-up truck trophy.

"It's a 2007 VE SSE ute, which I've had for about three years and have been slowly building it up to where it is now," he said. "It's got a fully modified engine as well as a custom interior with a big television and a big stereo."

Mr Garcia agreed that Summernats wasn't all about the burnouts and rev-heads. "For me this event is all about the audio and show cars, but that's just me."

Both winners said the crowds at this year's event seemed similar to last year, although official numbers found the four-day crowd was slightly smaller at just over 100,000.

One store manager, who declined to be named, said this year's crowd was slightly smaller than usual and her takings were 15-20 per cent less than last year.

Sunday was also a special day for John Saad, whose 972 Mazda RX-3 was awarded the street machine champion of the year,

"After the disappointment of last year, where I was in with a chance at Grand Champion only have an alternator fail, meant coming back and winning is special," he said.

Summernats co-owner Andy Lopez said the event was a success with "beautiful weather, amazing cars and terrific crowds".