The essential feature to look out for is video quality.
As with any accident, the officers had to keep an open mind as to whose fault it had been.
Images are saved on an internal memory card – a budget model with a 32GB card will film a four-hour trip.
Some more complex dash cams record other data, such as speed, exact location and even G-forces, all of which can help to build up a terrifically accurate picture of the circumstances of any accident.
It ruled all that out, and entirely proved my innocence.'Better still, when it came to dealing with the normally time-consuming and frustrating business of making an insurance claim, the footage was equally useful as it comprehensively proved the Astra driver was at fault.
Those of us unlucky enough to have spent weeks, if not months, wrangling with insurance companies in the wake of an accident will look upon Mr Pettifor's experience with an envious eye.