Parking inspectors, rogue mechanics and some of the worst driving is being captured on in-car video.
Dash cam sales are booming as the technology becomes a useful tool in gathering evidence for insurance claims and court cases for road rage attacks.
A Facebook page called Dash Cam Owners Australia is achieving cult-like status and has more than 200,000 likes.
Research conducted by Slater & Gordon Lawyers shows 54 per cent of Victorian drivers backed the use of dash cams and 39 per cent who did not have one wanted one.
But Victoria Police has urged caution with the devices.
"Police are aware of cameras being used in private vehicles to record driver behaviour and there is the potential for this footage to be used in prosecutions for traffic offences," Victoria Police spokesman Ben Radisich said.
"However, police are also concerned that the technology could pose a distraction to drivers.
"Distraction is one of the biggest killers on our roads and drivers need to remain alert and drive responsibly at all times." Dash Cams Australia expects to double its sales this year and sell more than 20,000 of the devices.
A woman managed to beat her parking fine after her dash cam recorded when she arrived at the car space, and a mechanic was caught thrashing a client's car on a test drive, unaware the whole thing was filmed.
Earlier this month, vision emerged of a truck driver's camera filming a Holden Commodore swerving across four lanes of traffic on the Princes Highway and showed how the truck narrowly missed crushing it and the occupants.
Slater & Gordon motor vehicle accident lawyer Craig Lynch said he expected an increase in the use of dash cam footage in Victorian courts similar to how phone camera footage was being used in some cases.
He said in-car footage was admissible evidence in a court case, as long as it was not used to film a private activity.
"At the end of the day, it will always be for the judge to determine the weight given to the use of dash cam footage in evidence," Mr Lynch said.
Dash Cams Australia recorded a 20 per cent jump in sales in October with 1200 units sold.
Sales manager Nick De Fazio said footage had been used to settle insurance claims when there were conflicting stories and were also a deterrent in road rage incidents.
"The amount of road rage is going through the roof and people want proof to show police," Mr De Fazio said.