The regulations state that a vehicle first used on or after 1st April 1985 must allow at least 75% of light through, and it is down to the DVSA and the police to ensure that vehicles used on the road are compliant with these rules. In the event that a speeding fine is issued but the images do not identify the driver, it is up to the registered keeper to declare who was the driver at the time of the offence, and if they are unable to do so they have to convince the court that they have taken all reasonable steps to identify them - failure to do so results in a separate offence punishable with six points and up to a £1,000 fine.