@Jan:
I've already done that.

Unfortunately, the diesel engine isn't the quietest.

That's why I can't hear the noise when I listen at the front. And the handbrake also makes noises, because the AFN engine has quite a bit of power. }
@Rainer:
I checked all the suspension components, even to the point of bending a screwdriver. They should be okay and tight (and they should be at 120,000 km). But the tip about checking the first gear without starting the engine and moving the car back and forth is a good one. I hadn't thought of that. I'll try it. Since the engine is off, you should be able to hear something if there's a problem.
'How are the rear engine mounts constructed? I've looked at the front mount, but there's no way it could rattle because it's made entirely of solid rubber. I've heard that the rear mounts are filled with oil. Can anyone confirm this?'