Holts Screenwash (£3 for 5 ltrs at Costco) does the job for me. I seem to fill up the washer bottle around once a month. So pouring filtered or bottled water would cost me an arm and a leg.
New Company car 2011 BMW F10 520D SE Xirallic Imperial blue/Cinnamon Brown 6FL USB, Front Sports seats, Sports steering wheel, Xenons - Arrived 3rd Dec 2010!
Scrapped RIP 12/08/2010 - E90 320si - Le Mans Blue - Totally standard specification
Long gone - 00 Peugeot 306 2.0 SE Cabriolet, 94 Rover 214 SEi, 91 Fiat Uno 60S Mk2