[ppbon]

... before driving off, look just above the puddle to determine where it's dripping from.
It could be an overflow in which case it will be just in front of the right rear tire.
It could be the water pump, in which case it will be in the front, right side of the engine.
It could be from the thermostat housing, just next to the water pump.
It could be a cracked reservoir in which case it could be from just above the muffler (check under the rear trunk's liner to make sure everything is dry.
It could be from one of the front radiators.
Or, it could be from a flexible or rigid coolant line running from the engine to the front radiators and back.
Happy Boxstering,
Pedro