The moment you realise your car has been stolen you need to contact the police in order to open a case. If the crime is in progress, dial 999 otherwise if the crime has already occurred you’ll need to dial 101.
After reporting the incident to the police, you’ll need to contact your insurance company and provide them with the crime number supplied by the police. This is to ensure if your vehicle is not recovered your insurance will pay out a sum to cover the value of the car.