here is my success story:
i was JUST approved for refinancing on my original auto loan. my original loan was with Chase at 6.94% APR. i refinanced with PenFed at 5.29%!!!!
i tried to do this earlier in the year, in august, and i was declined due to high debt ratio compared to my income. i just recently paid off a lot of CC debt and got my revolving ratio below 30% (i think i'm around 25% right now). from what i've read in these forums, that's the next best thing to having 1%-9% revolving use.
my current scores are as follows (as of this morning, prior to applying for the PenFed loan):
EX: 708
EQ: 685
TU: 701
i know that PenFed pulls EQ and i was suprised they were ok with a <700 score, but i'll take it 
i would definitely recommend PenFed to everyone. i am not in any way related to the military but i joined that one "military family" association (where you don't have to renew each year) and now i have a nice new cheap auto loan