[s-cars] Driveshaft "Squealing"

[Calvin Craig]

OK guys, here's one for you:

Patient: '92 S4
Symptoms: Squealing sound coming from underneath the car that is not rpm
dependent or gear dependent; it is simply "load dependent."  When I press on
the gas about 25%-20% throttle it squeals.  Any more throttle and it goes
away, any less and it goes away.
Diagnosis: Mechanic says that it is the driveshaft carrier bearing.  He says
it is a "non-serviceable" part but he knows a driveshaft company that can
rebuild it.

Questions:
Does that sound like the right diagnosis?
How hard is it to yank the driveshaft and carrier assembly?
Does anybody have a used one that I could buy?

The car has 193k miles on it and runs great but has a pretty rough body and
is not worth a whole heck of a lot of money, so putting $800 into it doesn't
thrill me.

Any advice?

Thanks!

--Calvin