Where is the radiator drain petcock on a 2000 Chevy Malibu?

It is possible this vehicle doesnt have one. If it does it will be at the bottom part of the radiator on the back side either on the left or right side. They move them during different years. If you cant find it then just disconnect the lowest hose and drain it that way. Sometimes it is easier that trying to find it. It does the same thing and usually more fluid comes out this way. I also usually fill it back up with water and then run the engine up to operating temp and then redrain. This will further flush the system. Then refill the coolant. Good luck. It is located under front splash sheild,on drivers side of the radiater!! check this area and you will find it.