However two quick questions. 1) I've already had the pipe at the front of the engine replaced by AR under warranty. They replaced the entire pipe for one which has a metal plug. Can you fit the metal plug to the original pipe?
2) As you're wondering why I still need a metal plug, THERE IS ANOTHER IDENTICAL PLASTIC PLUG AT THE BACK OF THE ENGINE! It's rarely reported but it was this one which expired on my car, I just caught it in time. It's quite deep and just to the left of the coolant expansion tank. AR do not have a metal replacement for this plastic plug and so just replaced it like for like. I'd like to see if the metal plug fits in this location as well.