Car loan interest rate?

Yesterday, I went to Toyota dealership to look at cars. I was inquiring about Yaris (cca 14 K sticker price). They ran my credit report which showed Beacon score of 638. I am a first time buyer, so I probably should be happy they are even willing to give me loan without co-signer. But when I asked about the interest rate, it was about 13 percent! I would end up paying almost 180 percent on that little thing. Anyways, I applied for a loan at my credit union, just waiting for Monday for reply. Is this possibly the best deal I can get? Or can I get a lower APR somewhere else? How about banks? I'm also willing to go to Carmax, do they have any good loans on used cars? The dealer said my score is ok, but since my highest credit limit shows as $2,000 (secured loan from my credit union), that's why lower limit on a car.