I'm sorry that this happened to you.  I have recently pulled and replaced
the fron differential, and can offer my opinion that the design of the
mountings used in this installation are quite good.  I am sorry that yours
came apart, but would suspect that there was a problem here not related
to any poor design by VW.

The three bolts through the rubber isolation mounts are fairly massive,
and use self-locking nuts.  They should not *ever* rattle loose.  Even
more, the original installation of these has the bolts installed from
above -- even if the nuts fall off, the bolt stays in play.  Repairs
normally reverse this, since the bolts are almost impossible to re-install
this way.

The front differential internally has a *very* expensive part called a
"viscous coupling" -- a "VC".  It has two "constant velocity" joints
where it attaches to the half-shfts (the front axles) -- or "CV's".  I
also am sorry that "CV" an "VC" and differentials all inhabit the same
space up front.

To me, it sounds most likely that somebody *attempted* to steal your
front differential unit -- probably to get the very expensive VC.  VW
wants something like US$2000 for this item, and they *do* go bad.  Even
*used* ones go for several hundred dollars.  I suspect they got the three
large bolts out, but failed to get the driveshaft attachment bolts off
the rear flange -- these are *hard* to get off.  They were probably
interrupted in their crime and you are lucky (you really could have been
killed had they managed to uncouple that flange, and the rear drivshaft
had come loose at 65mph!).

The three rubber mounts are industrial-strength mounts -- far stronger than
what is standard in any auto.  These are not difficult to replace, but you
would be well advised to check for other damage in the differential/VC/CV
unit, and the front half-shafts.  *Good* practice it to replace the bolts
that go through these (actually, just the nuts) each time they are removed,
but I confess that I never do.

The list members that flamed you are fully justified.  I have to restrain
my anger at the several incoherent messages that you have posted, but I do
realize that literacy is not a requirement for driving a Syncro, or for
being on the list -- and that English is *not* the primary language for
many of those that post.  I hope that it is not yours, or that you are a
poet or something.  If you want to ask for help, though, it is good practice
to VERY CAREFULLY state the problem.  We cannot see your car.  You have to
paint, with words, a clear picture of what happened.  Instead, we had to
use an incredible amount of imagination.

To summarize:  If what happened is that the three rubber shock-mounts and
one of the side CV joints came loose on your van, there is *zero* probability,
in my opinion, that this was defective workmanship, or VW's fault.  You
are a victim of an attempted theft.

Malcolm