Dealer Financing vs. Credit Union FinancingUse this calculator to help you compare financing between yourcredit union and low interest dealer financing. A dealer rebate,usually not available when you choose low interest dealerfinancing, combined credit union financing, can produce a lowerinitial loan balance, and in many cases, a lower monthly payment.The best option depends on the price of the vehicle, the size ofthe rebate and the interest rates available for financing.