Theres no way if it was leaking that much externally you wouldnt see it, there would be pools of it under the car or it would be sprayed all over your engine compartment. If it was dripping onto the exhaust and getting evaporated, you would smell it, if the heater core was leaking, the front seat passenger would be asking why is the floor all wet. If it was leaking internally into the oil, the oil would look like a milkshake.....unless the coolant was leaking into the exhaust passage either through broken head gasket or a cracked cylinder head. Either way....its under warranty, its the dealers problem. Just for interest sake, have the wife fire up the car after its been sitting all night and you stand by the exhaust, if a big white plume of smoke comes out and it smells like antifreeze than bobs your uncle, thats the problem.
