A court order for vehicle seizure due to a previous owner's tax debt is a problem that needs to be resolved through the courts and the traffic police, not by paying off someone else's debts on your own. If you bought the car with this lien already on it, legally the responsibility stays with the former owner, not you, but you'll only be able to lift the seizure through court proceedings - you'll need to prove you're a good-faith buyer and didn't know about the debts. You won't be able to sell or re-register the car in this situation until the seizure is lifted.
I'd suggest reaching out to a lawyer right away or getting a free consultation at the courthouse - they'll tell you what documents to gather and how to challenge the seizure. The main thing is don't put it off and don't pay someone else's taxes, that'll only make things messier.