My baby is only a couple of months old, and i've got the usual problem..i've used vinegar and newspaper, ag glass polish etc, but when i've cleaned my windscreen, i can still see the marks (just) where the wipers don't wash, like the dirt is ingrained..any ideas or suggestions?

You could try claying your screen then use a good glass cleaner after.

Meguiar's clay kit is available from halfords.

soak the screen with AG shampoo for a few minutes or snow foam it, jet it off then wash once more. once this has been done use the AG glass stuff and cover the screen, let it dry (takes a min or two) and polish out should do the trick.