It took all day, but I finally completed everything and drove off with my shiny, shiny, new '07 Mustang. I'm still in sort of a state of disbelief. Something along the lines of "That car sitting out there sure is bad-ass. Wait, that's my car. FUCK YEAH!" has gone through my head many times since I drove off the lot earlier.
In addition to buying the car, I got to have the somewhat novel experiences of both handling a piece of paper worth $18,000 (cashier's check), and writing a personal check for over $12,000.