I drive a diesel Ford Mondeo, its the second one I've had and a newer generation than the last one. Neither have presented me with any problems and any noise I do get is always from passing gasoline cars and their noisy sparkplugs.
You have not been around some of the oil burners in US. Stricter emissions and higher tech/very high pressure injection systems using quartz control injectors can cause RFI. Recent Ford power strokes can be a challenge. Proper resistor spark plugs with suppressor cables can quell it. When they are noisy it is generally because because cables or plugs are breaking down and need replacement.