Got a 2010 Skoda fabia 1.4 tdi.
Electric front window, manual rear)
Today while driving home after having my mot, I just pulled into a shop carpark & the passenger side electric window wound down & dropped  all the way down without my pressing the button. I parked up & the button on the drivers side door card wouldn't work the passenger window at all. Reached over & used the passenger side button & that just worked as bit intermittent 

Switched ignition off then on & the passenger door card button worked for me to get the glass up.
Driving on the way home it seemed intermittent & a press of the button on the drivers side door card sometimes operated the glass & other times seems to have a delayed action (could hear the motor randomly acting a few seconds later) 

Any pointers to look at? Was thinking it could be the drivers side window switch (cheapest option to change) or perhaps a broken or intermittent wire break in the bellows between a pillar & door? (Does this affect skodas like it does the mk5 golf?)
I haven't scanned it yet. Not sure if vcds would show the problem?
Thanks!
Mike
 

I don't think vcds will have any visibility of these modules.

Bellows wiring breaks are extremely common in the mk2 Fabia, start with visual inspection on both sides.