thanks for all replies, i use pure to see if it makes much differance and i think it does.tried it with my own windows and when i finished checked them to see big improvement. can i just say the cleaning of the glass was the same, but the detailing was a lot better i e just under the frame where i tap the squeegee was very nearly perfect so no need to wipe,also when some say why use pure because as soon as you put gg4 etc in it it s not pure,well, it might not be pure but it s not over 350 tds that comes out of my tap. cheers mick