Anyone tried this yet? Let me educate you in case you haven't done it yet.
Get a screwdriver and a funnel. The screen wash refill is located to the right of the small 'frunk' under the bonnet. It is covered with a removable panel which I ended up having to pry off with a key because I wasn't shifting it with my nails. This exposes a 6" inch square opening into the bowels of the car and the neck of the filler is down in there. I was in a Morrisons car park and had to fill it up or go home blind so I went for it. Without a funnel you are trying to hit a small opening surrounded by wiring and parts while the wind is blowing the stream of blue goo all over the place. It got on everything and also the plastic top cover. To cap it off (pun intended) the cap from the container of screen wash blew across and fell down the hole into the interior of the car. No clue where it went, I can't see it and have no idea how I would recover it. Be warned!