By the normal means?

The car cannot be taken regardless of the letter above if he doesn't own it. He personnally owes the money and they will take his belongings, auction them off and pay off the council. If they have not taken the car immediately then they have not siezed it. Make the reciept out and pre date it a month prior to the date on the correspondence you posted above. You will have owned it from this point on but your Dad is the registered keeper and regular user of the vehicle, authorised by yourself to use it (the owner of the vehicle, proven by ther reciept issued to your Dad. Keep a copy for yourself).

I would still try to come to an arrangement with the council to pay it back in small amounts.