My CU financed a car for my husband with a TU 643 score at 3.75% with 10% down for 3 years. This payment is also automatically taken out of account at this finance rate. Our CU scores are A+ 720, A 680, B 640, so you would probably fall into c category. They also offer a 1% decrease in interest if you have C credit and take the "Credit where Credits Due Class". According to our CU a C credit would get you a 5.75% interest rate. You may want to check into it. Most CU pull TU and they only pull once, unlike car dealerships. Best Wishes!
Starting Score: TU 573 Exp 523 Lender Pull, Eq 583