My car is an S.

The hose which came loose is the one running under the car and connecting to the front left radiator, I'm not sure if it has disconnected at the radiator or at a joint before it but it was dripping in front of the wheel......

This was no dripping though, it was a major spill which emptied the system in minutes....with the engine off and no pressure.....

Maybe the coolant smell comes from the back as per similar problems already discussed in the forum regarding the tank in the engine bay......or the recall about the engine studs braking the hose check it out....