Even if you have made payments for five years, if you stop making payments after that, the lender can still repossess the car. The bank will send a notice of default to the borrower 20 days before the repossession. After the 20-day grace period the lender has the right to repossess the car at any time.
However, some lenders may be willing to work with you if you are having trouble making your payments, such as by deferring payments or modifying the loan terms. If you are struggling to make payments, contact your lender as soon as possible to discuss your options.