★★★Yet while there are plenty of motorists who are convinced dash cams really do make life easier in the event of an accident, others believe they are the thin end of a disturbing wedge, in which insurance companies and law-enforcement agencies will be able to gather and collect data about yet another aspect of our private lives.
A dash cam is a small camera in a unit fixed to the dashboard or windscreen that records the road ahead.
As well as quickly establishing fault, many dash-cam owners say the cameras make them better drivers.
Among them is David Doyle, from Manchester, who was in his car when he was smashed into at a road junction by a driver who ran through a red light.
Globally, it is estimated that the market for them will triple to some £4.5 billion a year by 2022.
Kehan K300: £79.99 With medium video quality, the best thing about the relatively cheap K300 is that it offers a second camera that can film through your rear windscreen – invaluable if someone smashes into the back of you.
It is estimated there are already about 840,000 dash cams – including helmet-mounted cameras for motorcyclists – on the roads in the UK.