quangsta, going by that rationale, u could say that idling ur car for long periods is not good for your car. when idling, the engine is not working at its peak operating temperature so fuel doesn't undergo complete combustion. this means that fuel residues are left and they can contaminate engine oil and damage engine parts. water can also condense in the vehicle's exhaust which can lead to corrosion and reduce the life of the exhaust system.

an idling engine releases twice as many exhaust fumes as a vehicle in motion, polluting our air for no good reason. now, can u really put a price on the quality of our air, or for that matter, our lives? :P