The 35th Summernats was the biggest yet, with record crowd and entrant numbers, but the annual car festival was marred by poor behaviour from some attendees on Saturday night.
This year's festival was a sell-out, with more than 120,000 entry passes sold over the four days at Exhibition Park in Canberra (EPIC), and vehicle entrants capped at a record 2,700.
Crowd favourites such as the burnout and mullet competitions also attracted record numbers of entrants.
But the festival's cruise circuit at EPIC was closed early at 6pm on Saturday due to antisocial behaviour.
ACT police say the closure resulted in "a significant increase in poor behaviour within the venue", as spectators and drivers refuses to follow directions from security staff.
Officers were called to disperse the crowd and, soon after, police say some of the privately contracted security guards left EPIC, "resulting in an understrength security presence".
Police say the decision to shut down cruising early resulted in patrons and vehicles gathering in other locations across the city, including Braddon, Fyshwick, Majura Park and Hume.
In a statement, ACT Policing criticised Summernats organisers for inadequate crowd control.
"Events of this nature require an appropriate security response and ACT Policing is disappointed that organisers were not able to maintain good order inside EPIC," it said.
"The decision to cease cruising inside the venue resulted in patrons and vehicles dispersing across the ACT in numbers that were difficult to manage with existing police resources."
Police issued 20 infringement notices over the weekend and made a number of arrests, including for assaulting police, breach of bail and for being intoxicated and disorderly.
Police also seized four cars over the weekend, including a Holden Commodore being driven by a 20-year-old Murrumbateman man after he was caught allegedly doing burnouts and driving at more than 110kph in an 80kph zone on Barry Drive, near the city, at about 11:30pm.
The driver will face court charged with improper use of a motor vehicle.
'Disrupters weren't here for Summernats'
Summernats co-owner Andy Lopez commended the efforts of police and said it was the first time the festival had experienced such behaviour.
He confirmed the cruise circuit was closed early because of safety concerns, as too many spectators were walking onto the track and some drivers were refusing to listen to security staff.
"Those people were not here for the Summernats, those people were here to disrupt, so it's our job to make sure they don't come back," he said.
Mr Lopez said the organisers would work closely with security and police to determine what changes needed to be made.
"We understand now that [the closure of the circuit] had an impact out into the city, and I think that goes very much into the lessons-learned category and how we plan that better moving forward," he said.
"What happened last night was the implementation of a plan, should things get out of control in any one area.
"Now that we've seen maybe some ripple effects from that, we will work more closely with police to remediate that."
Mr Lopez said the festival had a "large security presence" and guards were told to withdraw for their own safety.
"That is a standard practice, and then manage that area and that behaviour with road closures," he said.
He said the first thing organisers would do was "make sure that that behaviour doesn't happen again".
"This is a fabulous event, with fabulous people having an awesome time," he said.
"We're not going to let the behaviour of a very small few ruin it for everyone, including making it difficult for Canberra.
Burnout and mullet comps prove crowd favourites
Summernats has worked to sell itself as a family-friendly event over the past few years, and Mr Lopez credited the record crowds to the festival's "increased offering".
More food, live music and fireworks were on offer, along with crowd favourites such as the burnout and mullet competitions.
Nearly 40 drivers entered the Burnout Masters this year, with the final 15 burning rubber on Sunday afternoon to determine a winner.
Jake Myers was declared the burnout champion in his S1CKO Mustang.
Livi Krevatin, from Michelago, was declared the overall Summernats grand champion with his custom-built 1978 Porsche 911 SC Coupe, winning on appearance, quality and driving performance.
A record 110 mullet-toting revheads took part in the Dirty Mullet Fest, where competitors were judged on the style and length of their hairdos as well as their stage presence.
The competition was broken into different age groups and categories, including everyday mullet, extreme and vintage.
A surprised Tamzyn Dowell was named the overall winner after entering the competition for the first time.
"They're the most beautiful haircut: business at the front, party at the back," she said.
"I love them; I think all mullets are good."
The 18-year-old from Wangaratta said everyone in the competition was "super, super nice" and Summernats overall had been "so good".
"The atmosphere's been great, it's been really fun."
This year's Summernats injected an estimated $35 million into the ACT economy.
An ACT government spokesperson described the reported antisocial behaviour as "disappointing".
"As is often the case in society, the poor behaviour of a minority detracts from the experience of the majority," they said.
"The government supports the actions of ACT Policing.
"Safety and security arrangements for the event are reviewed with Summernats organisers every year."
