The check for payment goes to Pentagon Car Sales, not BMWUSA. I have bought two cars from Pentagon (An 04 and an06).
They will describe exactly how to do it in an e-mail to you. It must be a cashiers check. Payment will be in full. I was a little nervous about doing it. But everything went smoothly
The local dealer here will do a courtesy delivery. That is coordinated by Terry Brennan at BMWNA in New Jesey. The local dealer gets a small stipend to do it. I've been told that it just about covers their costs to prep the car. They don't make a profit, but do it to establish good will.
The dealer will probably take the MSRP sticker off of your car as it shows the military MSRP which is much lower than the other cars on the lot. Any other questions I'd be happy to answer. I think you will be glad you went this route in the end. I understand the anxiety about dealing with a distant entity by phone and e-mail.