[ohioboxster]

Open the trunk and look at the coolant tank it has sight level. You will be able to tell if antifreeze is missing. It could be a couple of things and I cant imagine it has anything to do with the heater. Antifreeze and oil have two seperate smells. I think you must have a coolant leak and its dripping on the exhaust. Do you know how to put the car in service mode? The coolant tanks in the trunk are known to leak as well. The red light on the temp gauge will flash when coolant is low, mine did when it was about a cup low.