Wayno and I are currently busy with a friend's Corsa C (Gamma) GSi where both the rear electric windows decided to no longer work.
On the one side the cable and motor were physically broken after someone tried to break into the car while on the other side the window simply stopped working - at first we thought it was the motor.
After removal Wayno sourced a recon'd motor to replace the broken one. What we also found is that the guides that keep the cables in place on the arm of the mechanism is made of plastic and they were both broken... and course these are not sold separately.
Quote from GM for two new mechanisms ~R5000 ... each.
Eventually Carl recommended
Cable Clinic and it turns out that electric windows are one of their specialties, including the repair of any broken bits. Prices start from ~R700 per window and can go up to about R1300. In this instance we paid R1400 in total for both windows, including new cables and replacement of all plastic bits that are broken. And they offer same day service.
Have to say that their service up until now has been awesome.
We're collecting the mechanisms today and I'll comment again about the quality and workmanship once the windows are working again.