I am in the early stage of developing a rotating 12v brush head, now i have tested it on my prototype and it works realy well. even under pressure against the glass it keeps rotating, simular to a car wash brush,one end is completly open so it gets right into corner,simply turn the pole and you get the reverse,so you can do left or right corners. i think this will mostly benifit comercial users 30ft and up. so does anyone think it would be any good, i dont want to waste my time,any feed back would be appreciate thanks jouk45