Originally Posted by
MSPeconomist
It's better to have the confirmation number (for a reservation that is already checked in) than your name or room number. The hotel wants some way to identify the car's owner/renter/driver if there's a problem, such as if the car is damaged or needs to be moved.
If the hotel needs a way to identify the owner of the car, there are other ways (more respectful of privacy) to accomplish this, such as requesting the license plate number.