With a 667 score, you’re not in the top tier, which ranges from 781 to 850, but you’re still in the prime level. The average car loan rate for this tier is 4.21% for a new car loan, although this will depend on your lender, your credit history, your income, and the length of your loan.
Because $20,000 is relatively inexpensive for a new car (most new cars are around $40,000), you position yourself even better for approval. So make sure to shop around and find a lender willing to work with you.
Best of luck with the loan!