If you ordered the car and have the paperwork, the car is yours.
If I were you though,
just to seal the deal since you are going to be away for a week, I would put a deposit on it.
Make sure it is refundable and explain to them the situation.
That's how I would handle it.
(Make sure you tell the salesman/manager at the same time of explaining your situation as to not have any confusion and have everyone on the same page.) AND, have it writing.
GOOD LUCK!!
