Spark plugs

Those plugs look just fine. The "rust" you are seeing is common with plugs that have miles on them. It is because they are in a bad environment for metals. Constant heat and cooling cycles on the metals and the combustion gasses that get into the threads all work together to try to destroy them. If the gaps are okay, I would likely give them a quick scrub with some brake cleaner and a plastic brush and put them back in. Unless you want to change them just as a preventative. But it's your money.

Thanks for the reply, yea Australia tends to get super hot throughout the day and chilly cold at night. Explains the rust built up...

Would change just as a preventative since i just got this car with 180,000 miles on it.

That will do it, but the engine itself bakes them real good as well. I would likely do the same thing if I bought a high mileage car, That way you know what you have. Thank you for using 2CarPros.