The best auto loans finance rate

I am planning to buy a used car from a any car dealer within my state, But they are too many car dealerships to choose from. One car loan financing agent told me that an auto loans in easy to get with the right credit and loans. However, i am not sure, what is a reasonable or deal car loan? most used car dealers have very high interest rate for the auto loan financed which makes it hard for a rookie car shopper to find a reasonable car loan.