Plastic leash, holding the lid of the Opel Astra J petrol tank, is not too strong and can be cut off, especially during the cold time of the year.
Replace the leathing with plastic shackles (fastenings) that are commonly used to wire wires. It'll take three hammouts. The first hinge needs to be done in the petrol tank cover and a noose to which the second hinge is attached. Then it will be necessary to drill a hole in the loop of the gas tank and also make a pellek to which the second end of the hinge will be attached.
