Nevertheless, what I did when I needed to give mechanism - mechanism completely taken out, but window was fixed in place - shut - with wooden parts put in the door that are firmly holds it in place, and you can not lower it down, but also it will not go down as wood holds it.
That sounds good - I have some plastic wedges and anti-slip mat (rubbery) which would probably do that job well.
Also I am interested to hear your thoughts about the window switch-pack!
OK, well the first thing that struck me was that people were saying that a short-circuit ("short") caused the pack to catch fire, but the fuse didn't blow in time. This is unlikely, as that's the job of a fuse: in an overcurrent situation to blow before the cables get hot enough to catch fire. It's much more likely to be overheating for a different reason.
Looking at the 2nd-from-last picture in message 8 of this thread (that shows the fixed contacts without the copper moving contacts), this is obviously two centre-off changeover switches, so that in the off position no contacts are made, in the forward or backward position contact is made on that side between the fixed contacts and each fulcrum (pivot point).
I noticed that the top-left and bottom right contacts were clean, with indication of a decent-sized contact-area of each, and above the bottom-right contact there's a "flare" of clean area with a slight covering of dirt either side. This suggests that there has been an arc on these two contacts, presumably as they separate. This is a Good Thing as long as it's brief and doesn't get out of control, as it cleans the dirt from the contact area and around it (actually it vapourises it, as it's extremely hot).
Now look at the other two contacts: covered and surrounded by dirt! Hardly any contact area visible on the top-right one, where there's barely a pin-hole through the dirt. It's unlikely that dirt is deposited only in opposite corners, so it must have arrived but then gone again.
The fulcrums are asymmetrical - closer to one contact than the other and due to this the contacts make/break at different times, the furthest one would separate first, so the separation arc would form there, cleaning that contact and then breaking the circuit so the other contact would separate "dead", with no current flowing, so there's no arc there to clean the contacts and the dirt can accumulate.
As the dirt reduces the contact area, it increases the resistance and causes reduced total current flow but higher current-density at the contact point, so heating the contacts. The heat has to go somewhere, and copper is a good conductor of heat so it will go down the cable, and may start melting the insulation or the plastic block around the contact. Depending on what the dirt contains, in extreme conditions it may heat up enough for it to catch fire.
As the total current flow is reduced, it may not be enough to trip the "Auto" solenoid to release the switch when the window reaches fully open, which means the motor would remain energised but stalled, so the current is flowing and heating the contacts for much longer than a normal open/close cycle (only applies to opening the driver's window, obviously).
So, assuming this is something like correct, it means that cleaning the contacts periodically (every 5 years, perhaps?) is something that any 600 owner should consider. And if any drink has been spilled down there, it should be done sooner rather than later, as sticky liquid will hold dirt particles very well, accelerating their accumulation. And if the switch sticks in the "Auto" position, un-click it yourself!
Anyway, that's my theory and I'm sticking to it! :-)