Underground prison

Private subterranean garages offer security for your vehicle for those who can afford it.  However, this bit of luxury comes with an added price tag.  Once you pull in and the gates roll back after your car, you are essentially trapped underground.  Who knows what could have darted in along with whoever entered before you.  What could be waiting for you down there once you are trapped inside could be worse than what could have happened to your car had you parked it on the street.  The desolation underground is sometimes the perfect setting for those who wish to do harm.