Well, I suppose the phosphoric acid might have some cleaning effect, and coke has been known to clean various other items. But I'd have a problem with the sugar aspect of it though - I could just see it collecting dust.

The Brits will appreciate the Chip Shop issue.... Just how do they keep the glass of the hot display cabinets clean around all the greasy food and fumes. The 'secret' is basically what has been discussed before - get the gunk off with detergent and water, dry, then wipe down with vinegar and paper. In the old days newspapers were used, but nowadays they just use that plain wrapping paper.

BTW, the combination of ammonia, vinegar and detergent is extremely powerful as a cleaner. It also releases unpleasant fumes that could make you feel rather giddy if used in close quarters. I wouldn't have thought that anyone's car windscreen needed the ammonia, unless of course, one of their passengers has projectile-vomited after a night of beer and curry.