Gotta colleague who has above car and it was only firing on 3 cylinders.
Local garage did new ignition coil and HT leads.
Since then she has been aware of vibration noise and it has cut out a few
times. Returned to garage who did a test drive, could eventually hear noise
and the car did cut out. Cuts out when warm, not just from cold. Garage have
spent 1.5 hours today trying to isolate vibration noise - it is plasticky
and seems to be related to revs. He has tie-wrapped a few possible bits but
still can't find it. Says that it is nothing dangerous.

BUT the guy says that the oiled is black and overfilled - turns out she got
a "litre of oil for a modern engine" and poured it all in a few months ago.
She has owned the car for 8 months and not sure when it was last serviced.
Methinks that his quoted price for an oil./filter change of £49 is a bit
steep - but it needs Ford Zetec oil, 5 - 40w apparently. (local Ford dealers
do it for £45).

So . . .  I think that it needs an oil change anyway as it has only been
used for local journeys. Any ideas tho on what could be causing the cutting
out problem please? Garage guy suggested that cutting out could be caused by
poor oil flow when cold????? Never heard of that myself.
Focus Zetec oil & cutting out problem, 1.6 V Reg