One of the best reasons to refinance an auto loan is if you have an opportunity to lower your interest rate. If you previously had no credit or had a bad credit history, it's worth considering refinancing your car loan after a couple of years to see if you're getting better deals. Your credit score may have improved enough for you to qualify for a lower interest rate. With a lower interest rate, you can pay off your loan faster or lower your monthly payment while paying it off at the same rate. In either case, you'll pay less over the life of the loan.
You may pay refinancing fees. Refinancing a car can include a variety of costs, such as application fees, origination and transfer of title.