I see your blue passport and raise you a green number plate: UK mulls rewards scheme for zero-emission vehicles
https://www.theregister.co.uk/2019/10/22/uk_green_number_plates_to_help_cut_carbon/
The UK government has a cunning plan to help meet its carbon emissions targets: green number plates.
Today the Department for Transport published a consultation on the number plates (PDF) as a way to allow zero-emission vehicles to benefit from incentives such as cheaper parking.