I have a 05 300c and noticed I have a coolant leak in my petcock area. I haven't looked to see if its loose because I had just got done driving and the car was hot. But looking down through the engine bay I seen it pooling a little on the black guard/shield near the petcock witch was wet when I looked under. Its not a heavy leak because I havent noticed marks on the driveway but noticed im loosing coolant. Im wondering just incase, can you replace the petcock on these model cars or do you have to replace the entire rad? I've done sum research and seen a 1aAuto video where the tec briefly runs through coolant issues, and said if the petcock is busted or leaking you have to replace the Rad. But I've noticed you can buy a oem petcock for like 10 or15bucks at orallys/autozone? I am not no mechanic but I do have common sense so any help will greatly be appreciated..thanks in advance!