[Mike]

Anyway how does clearance work in this regard when its all come from some police dashcam in the first place? Normally from what I understand you often have to pay to clear something, but while I appreciate the police own the copyright, do they (or the police forces) make anything from these sort of programmes, of recording somebody basically doing something stupid on the road?

Absolutely nothing from a UK point of view.

The police can't sell the footage in the first place, as it's 'crown copyright' - as in material produced by the crown or servant thereof in the execution of their duties. It would be released usually post charge or pre-charge if no distinguishing features can be made out (hence why repeats often have faces blurred, as at the time of rebroadcast the conviction would've been spent).

The payment the police got was more in kind from these things; for instance the effects drink drivers can have on other road users and showing things like that, along with a hoped increase in public confidence that they are targeting offenders.