<E34> 1992 525i, Squeaky window

[Peter Biernacki <pbiernac@xxxxxxxxxxxxxx>]

The car in question is a manual 1992 E34 525i with the M50 engine.  (7/91
production date).

Does anyone know how to remedy a driver's side window that squeaks
and squeals when going up and down?  What should get lubricated and
how to do this?  What product is best to use (I have heard of a BMW 
product that seems appropriate for the job; BMW Universal Slip Agent Spray
P/N 81-22-9-407-711).  Any advice?  Thanks.

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