SticKing1 made a nice recommendation with the Alcohol/Vinegar/H2) mixture. I have yet top try it since I ordered a case of the stoner's IG (12 cans) a while back and still have about 3/4 gallon of Eimann Fabrik Clear Vision.
I was looking into shipping you a can or two of the Stoner's but it costs $32 for a 5 pounds package to the UK from the States in a time frame of 4-10 days, or $38.75 for 3-5 day Global Express Mail.
To ship 12 cans (about 15 pounds) would cost $62 for the 4-10 day service, or $68.75 for 3-5 day.
A case of the Stoner's costs $32.83 or so (shipped to me.)
BUT, that seems a bit excessive for a window/glass cleaner.
A damp Mf followed by a dry mf for buffing does wonders though.....