My drivers side window motor packed in. I discovered, when I took it to an independent Porsche repair workshop, that the supplier had no stock and apparently they are on back order from Porsche in Germany, but he no idea when they could supply one. Also, even if they could supply one it would cost £170.
I did some research and discovered that that the window motor is made by Bosch and is the same motor fitted to a Saab 900! To my delight I found a place who had loads of stock and sold me one for £55 delivered...a great saving and no problem with stock! I have now had it fitted and would recommend them.
Order the motor from here:
http://scantechparts.co.uk/acatalog/Window_Lift_kits_and_Motors_Saab_900_Classic.html#a51_2e821036The part number is
51.821036 (Window Regulator Motor, Front, RH & Rear) for drivers side motor, and for the passenger sidce it is
51.821037 (Window Regulator Motor, Front, LH & Rear). I understand that these motors may not be compatible to earlier 928's, which have less teeth on the cog, so best to check first.