The core plugs are located around the cylinder block, not sure how many but if you follow the trail of leaking coolant or look carefully around the engine and hose connections for water marks you will find the leak. If this doesn't help check your carpets for dampness, mine leaked from the heater matrix inside the car which I fixed with a leak stopper that had been specially developed for leaky rover head gaskets. (Good stuff too, actually fixed my wifes freelanders 2'nd head gasket as well) if your heads gone check your oil for creaminess of colour. Also with an assistant, take the radiator cap off the COLD ENGINE, top up the coolant, leaving the cap off start the engine, assistant covers exhaust pipe with their hand, if you can see air bubbles coming up through the coolant this is exhaust gases leaking through the head gasket into the cooling system.
