Check with your credit cards first and see if any of them have your free FICO score. It's wont be the same one that the bank will pull, but it will give you a general idea of what your scrore is.
Then, call several banks and credit unions around you and ask for their rates and terms with the FICO score that you have. You probably already know this but, DO NOT LET THEM RUN YOUR CREDIT!
Once you have those rates, Go you your dealer and ask what rates and terms they have for your FICO score. You probably already know this but, DO NOT LET THEM RUN YOUR CREDIT!
Once you have determined who has the best rate for you, go with them. And remember never negotiate a monthly payment with a dealer, they will screw you with a longer term loans for a lower monthly payment. Had a friend that ended up with a 96 month loan negotiating on a monthly payment.
And sometimes, Ford Finance has a rebate if you finance with them. The rate might be high, but they have no early payment penalties. When that is offered, I usually take ford credit, get the rebate and then refinance with a bank at a lower rate after I make my 1st payment. My last F150 had a $2,500 Ford Financing rebate, I paid an extra $30 for that 1st month financing and the $100 refinance fee from my bank. $2,377 less for the truck was well worth the hassle.
2011 Fiesta SE Hatchback
2013 F150 SuperCrew FX4
2014 Mustang V6 Premium Convertible