I am NOT an expert, but I think this is how it works....
You get a Purchase Order from the dealership and take it to AFCU, and they will approve you and you are good to go. It does make the interaction at the dealership ALOT shorter.
I think the challenge is the Tax Title and License. I think the dealership can give you a "transport license", although that seems to vary from state to state (i.e. New Mexico told us we needed a transport license, while Nebraska said we didn't).
As far as being stuck when you get there ... yeah, you are kind of stuck. Not sure how to get out of that part.