I don't know about other manufacturers, only Toyota. I only know this because we just bought a replacement Highlander for my wife after her two month old new highlander was totalled in a wreck. Toyota will give you the zero percent only on selected vehicles at selected times. Otherwise, it's all about your credit score and down payment. To max out, you need both to get the lowest rate from Toyota.
What I meant by my comment above on "not making much difference" if you have great or "greater" credit score is this: A few points one way or the other won't make a difference. Excellent credit is 750 or above. If you have 750, 760 is not going to get you a better rate.
Good credit is 700 to 749. If you have a score of 740 and you bump it up to 755, then you might gain a few tenths on your rate. But, it actually takes quite a bit to change your score substantially, and losing a few points by paying off a loan early is not going to change it substantially. That's what I meant.
Ford is not Toyota and like most of the 'Big 3' they offer rate incentives almost all of the time. Most car dealers consider you golden if you're over 720 and when I buy anything that doesn't offer 0%, I get pre-approved through my bank (USAA) even though I'm sometimes giving up .5 or so because I'll gladly pay that .5 to know I get someone that's based in the US and speaks English if I have a problem. I understand what you're saying but he's buying a Ford that isn't on the exclusion list so 0% shouldn't be that hard to come by or require money down.