The weakest link in the NC cooling system is the plastic expansion tank that is prone to early failure. When the NC Miata expansion tank fails the coolant system will quickly have zero pressure and that compromises cooling system efficiency such that the motor will quickly overheat and often fail before the owner has opportunity to notice the tiny hairline crack on the back of the plastic tank. Thus we suggest our METAL Moroso NC Miata Expansion Tanks Below as good insurance against early motor failure. We also suggest our upgraded Miata radiators to any customer looking to track their NC generation Miata. Customers planning to some day add boost, whether turbo or supercharger, are encouraged to future-proof their NC with our Triple-Pass Performance Miata Radiator. With any radiator installation you MUST check clearance to AC condenser, factory condenser installs not real consistent and you want to make sure nothing will rub a hole in the new radiator, bend consendser brackets for clearance as needed.