New Government Regulations require vehicle manufacturers to offer Free Take-Back of their vehicles. Under the "End of Life Vehicle Directive", centres have been set up around the country to dispose of your vehicle in a sustainable manner.
If you wish to dispose of a vehicle yourself, you must take it to an authorised treatment facility (ATF). Here it will have pollutants such as fuel and engine oil removed, before being sent for destruction. A list of these facilities can be obtained from the Environment Agency at:
Environment Agency - Authorised treatment facilities public register list
Welsh Government - End-of-Life Vehicles (ELVs)