I'm in a similar situation, and will summarize what I've seen.
You will find that the credit unions have hugely different terms, rates and requirements.
You will find from 0% down to 20, terms from 5 to 15 years, and rates of 5.99 to 13, seriously.
I'd say the average you should expect is 10 years around 8.
The keys are value, basically you need to be below NADA, some will accept surveys. Some don't care about year at all, others need very new.
Also, debt to income, and it can have a big range of what they're looking for. From 40% (or actually 50% of net at one place

) to 50% at some.
I've also been getting turned down based on length of employment, as I've only been at this job for 9 months.
Basically, there are plenty of good rates and terms that will be exactly what you want, but they have 100's of ways to turn you down, and seems they are eager to (or perhaps its just because I'm in the auto industry

).