Having your credit checked as you try to find the right option for you can cause your credit score to dip very slightly, probably between one and five points according to the Consumer Finance Bureau. However, they note that for auto financing, the credit scoring models often factor in that you’re shopping around and therefore multiple credit checks are likely to count as only one credit check, if done within a relatively short period of time (around two weeks).
First, check your credit score for free at FreeCreditScore.com. If your credit score falls in the 620 to 650 range, you're actually fine. You should be able to find financing from more than one source. If your credit score is between 550 and 620, you're going to have a more difficult time, but there is definitely hope. If It's below 550, you're in serious trouble. If you can even find financing, it's going to be at a very high interest rate.