About 2 weeks after you make the last payment.
If your name is on the title, you can take the car. Just make sure he didn't re-titled it after the split.
Who? If it's your parents then yes.
It will likely be repossessed and sold at auction, if not redeemed, with the proceeds being applied against the amount owed and subsequest repossession, collections, and legal fees.Keep in mind that...
Not unless you have something in writing that states that they are to make the payments.