I have a 2005 Saab Diesel manual. It has done 165,000.
There is faint metallic noise when the car is in neutral, which doesn't always go when I depress the clutch. However, halfway between my foot off the pedal and pushing down fully, there is a terrible grinding metallic series of noises.
Also, when I am driving along and say I am going down hill and let off the accelerator, there is another noise.