Avoid paying ulez or any other charges against your car.

Create a Lien of claim or mechanics lien against your car, that way if someone does come to repossess it, it will have a charge against it that they must satisfy first.

The charge will be payable to you, after all you have cleaned and cared for your car all these years you have a right to put a charge against it.

Make sure the lien is for far more than your car is worth. If the car is worth £12,000 then make the lien for £100,000.

If they do take your car and sell it they have to pay you £100,000 for the privelege.