How does a blank check auto loan work?

[Anonymous]

I just got a promo code from Alliant Credit Union about my low rate auto loan waiting for me. I've been thinking about getting a new car, but am unfamiliar with doing it through a credit union. How does this work? Is this a blank check loan? Do you need to put a downpayment down when you get this? Any insight would be helpful.

[Loquat]

It depends on the offer.  Blank check auto loans use to be really popular in the past.  CapOne and HSBC were really good about sending those things out.  

Now I only hear of credit unions doing such.  Typically with check drafts your lender will approve you up to a specific amount and usually have some requires such as a age, miles, and who you can purchase from (i.e. dealer vs. private seller).  You often don't have to put money down unless you're trying to purchase outside of your pre-approved amount.  

Are they legit loans, absolutely.  This is the only way I'll purchase a vehicle.  PenFed/Navy Federal/DCU are my lenders of choice unless captive finance has a really good offer.