I was just wondering. I know getting to the heater core is (well pardon my french) but a bitch to get to. Out of curiosity though. Is there any way possible that if someone ever needed to replace there heater core. Can you also install a positive temperature coefficient along with that heater core just like some of your higher end cars have? That way on initial start up of the truck during that 0 degree weather your not waiting for the engine to warm up to get your heat. But instead you have instant heat right then and there. And then once your engine temp ranges out to normal operating spec, the coefficient shuts off and your system runs off the normal system using the coolant and heater core.