The $10 donation is part of the joining online process- you pick which thing you want to donate to- and then when you fund the account (also during the process) you simply add that $10 to your funding and it goes from you->account->donation target automatically.
Join Allegacy | Allegacy Federal Credit Union
Just join there. Where you live doesn't appear to matter (though I think they did ask if I was a US citizen)
You get your account number on screen once you've been approved for membership (this was instantly for me after submitting the application) and then get an email with your member number.
You can apply for the loan without the member number if the email is slow or something, you'll just need to provide it to them eventually.
New Car Loans | Allegacy Federal Credit Union
Hit apply now to apply for it.
The best rate (2.29%) is for loans up to 66 months- the website does say they'll do 100% finance but I had "10% down" on my app since I was expecting $ from a trade in going toward the purchase.
The 2.29% rate also requires auto-draft of payments, but you
do not have to autodraft it from an Allegacy account, you can give them the account # for an account with any bank and they'll draft it from there.