If the vehicle is on Hire Purchase, then they require court action to take the vehicle back if you have paid more than 1/3 of the total amount that is due under the agreement.
You would have to have been issued with a termination letter as well as documents telling you about the legal action. They would have to go to court and prove their debt (the agreement) and unless you can show that you have paid etc then the court would probably find in their favour and they could then repossess the car.
If you have not paid a 1/3 of the amount due, then they can justtake the vehicle without going to court first.
The amount of time is irrelevant