I've read through various entries on the site about various vibrations on a 406 HDI 110. Now, as I'm about as mechanical as plank of wood, I am none the wiser though do see many references to DMFs (and yes, i actually do know what that means

As I said, the noise is intermittant. There have been times where I have been running the car for say 20miles, stopped and turned ignition off and there's been no vibration during the journey. If I immed restart the engine, the vibration sometimes just appears. Like I say in the topic header, the noise is a vibration I can hear but I cannot feel a physical vibration through the pedals, wheel or body of car.
It's going for MOT on Saturday and I'm going to ask the garage to take a look at the vibration but was wondering whether the 406oc had any thoughts?
I need to get it sorted asap as we sold my wifes' Astra to accomodate the 406 and she's now refusing to drive it (she's thrown me the keys and has taken over my 2009 Mazda6- not a fair trade!)
Scaramanga