I am having problems with my 04 Grand Prix...go figure. So couple days ago i noticed a weird smell like antifreeze or something in my car didnt think much of it. Also, I noticed my air was not as cold as it usually is. Well yesterday on my way to work my car started rumbling at a stop and I looked down and my engine light came on and my computer said "Shutting off air to protect engine". My temp gauge was past the red and smoke started pouring in through my air vents all on the INSIDE of the car. Pulled over let car sit and then checked Antifreeze to find it was bone dry. Took to friends work down the street let sit all day then put more antifreeze in only to find that it started leaking drip drip drip from two places under my glove box. So...everyone has been telling me its my heater core. Could it be anything else?? If not and it is my heater core I have heard it is hard to replace on this car. Like 400$ labor!? Which I am not into. Can it be done by someone just following directions or should I have it taken to a shop? Also is there any way to get around replacing it like bypassing the firewall and just have my heater not work for a while?? ANY suggestions and help would be much appreciated thanks!!!