If you’re not able to pay your loan by the maturity date, your lender will probably charge you a late fee. You’ll also continue to accumulate interest on the unpaid parts of your loan, meaning it will get more expensive over time.
Once you do pay off your loan, though, your lender will relinquish any claim to your vehicle. Your promissory note will also be retired, releasing you from financial responsibility. At this point, you’ll own your car outright!