Loans and credit checks?

-I want to apply for a loan to buy a new car but am worried about the credit checks. Nationwide advertised 6.6% APR but when I applied the rate went up to 10.4% which I cant afford, so I didn't accept. I have excellent credit rating but all of the loan providers advertise a rate then in small print state that the rate varies per person. Is there a way to find out what apr rate I will get without them having to do a credit check? I don't want to have to apply to loads of different companies just to find out what rate I will receive. Will that look bad on my credit history?