Small story for you, last Ford Fair...
Screen was smearing for some reason, remembered I was behind a Larry st some point and realised it must have been the spray/dirt, tried spraying screen wash... Nothing just made it worse, so going past the Autoglym stand I decided to buy the 5 litre bottle of the pink screenwash, which I use, saves money in the long run!
DO NOT LEAVE THIS IN YOUR BOOT
I made this mistake... Car smelt like a chemical plant and looks like someone had wet themselves in the back of my car, it literally got everywhere. My eyes where stinging all the time and I got headaches , nobody wanted to get in my car. Even after getting it cleaned out it was still there and would just appear somewhere else.
About 4 litres of the stuff leaked out as the cap had become unturned and I forgot about it... 20 quid, kept my windscreen nice and the insides of my windows clean, but turned my car into a transportable bottle of bleach.