That sounds familiar.  I had the same failure on an '02 ZX5 that was
about a year old.  One rear window regulator broke.  I had it replaced
under warranty and 3 days later the other one went out.  This was also
replaced under warranty.  When the car was a little over 2 years old I
sold it to my brother so I could buy an '04 SVT Focus.  Just before
the original 3 year warranty was up the driver's window regulator
broke so he got that done under warranty also.  So far it's been
almost a year now and he hasn't had any more of that kind of problem.
He's been a bit nervous about the passenger's side but it hasn't gone
yet.  My SVTF is around a year and a half old now and "knock on wood"
I haven't had a single problem with it.

So I don't know how common it is since your case and mine are the only
two I've ever heard of.  We've got a local Focus club that has quite a
few members and, as far as I know, none of them have ever had that
problem either.

In any case, good luck.

me/2

Exactly the same happened to my 1999 Focus 1.8 LX 5 door. The window that
failed was the front passenger side one. My son was just lowering it and
basically the same thing happened, although nothing actually broke. The
cable was so badly damaged as it had wrapped very tightly around the plastic
pulley it came off, that the whole assembly which included the motor had to
be changed. The car was about four years old when this happened and had
covered only about 24,000  miles.

I seem to remember the part alone was around £150 inc VAT, plus about £80
for fitting.

I wonder if this is a inherent problem, and if it has been addressed on the
later Focus's - not the latest shape ones.

Hope this info helps.

Mike - Northern England, UK.