for a while the drivers window would sometimes refuse to go back up, mess around with the switch and you could get it, or put it up with the remote no problem.
its been on the to do list for tooo long. Anyway, car was off the road for a flywheel and as soon as i got it back it was up for MOT. I rocked up to the MOT center and put my window down, it stayed down through out and I passed no problem.
It wouldn't go up on the switch so i pulled up to lock the car and roll the window up as it was supposed to be a wet day -no joy.
the battery has been disconnected and its lost its memory...FFS. At this stage i had to go to work and it spent the day with a bit of bubble wrap to keep it dry.
when i got home i followed this to remove the switch Change switches for electric windows on drivers door Audi A6 (C6 4F) - ! extra bolt see description! - YouTube only i didn't fit new i was able to split the switch and clean the contacts.
The switch works a metal spring set up which contacts pads on a PCB, it was one of these pads which was black and not allowing contact.
nothing went flying when i split the switch, its all secured in there.

all sorted within an hour , just thought i would put this here for reference.