Interesting question. BMW NA should be able to answer it or talk to BMW AG for you if necessary. Make sure you let that employee enjoy his/her time in Munich for a bit rather than taking two very long flights back to back -- though of course one of the perks need not be your car!!
FYI though have you thought about sending a friend instead? If I were you I'd feel awkward asking one of my reports to do this, or to be asked by my boss. A friend would probably be cheaper too; if you paid their airfare and at least part of their lodging they probably wouldn't hit you with an expense report for everything else.