Don't know how obsessive you are about swirls in your paint, but if I were you, I'd beg the dealership not to wash the car before delivery. All other prep steps, yes, but not washing. (Don't forget to have them turn off the back-up beep, unless you love being reminded that you're in reverse.)
For details, consult the happily insane bunch over at autopia.org, a detailing site. You needn't go as far as they do, but even I (a relatively normal car-care devotee) have personally experienced swirls created by dealerships.