In the short-term, don’t be afraid to shop around. While you should be wary of the number of applications for finance you make that involve a hard credit search, a comparison site or finance broker can help you check your eligibility with a panel of different lenders at the same time. This allows you to compare the loans available to you and their APRs with minimal risk to your credit score.
Every car finance provider should also have their representative APR prominently displayed. While there’s no guarantee you’ll receive this amount, it can provide a good indication of the kind of APR (or lower) that most customers are able to secure with that lender.
In the longer-term, taking steps to improve your credit score can help you secure the best possible interest rate in the future.