Not being very sure on what an eraser sponge was, i did a quick search and found a place selling Autoglym magic sponges (which seems to be an alternative name for eraser sponges). Didn't mention anything about windscreens, but it does say this:

– Pack of 10
– Use for effortless removal of stubborn scuffs & blemishes
– Can be used on decorative vinyl & plastic trim
– Will remove scuff marks that traditional cleaners won’t shift on things such as interior door panels, kick plates, luggage compartment, boot, estate car load area, seat backs, plus similar surfaces in trucks, buses, boats, caravans and around the home.

Instructions:

– Dampen the Magic Sponge and rub it vigorously over mark
– Avoid using on glossy surfaces which could become dulled

But when i used to valet cars the windscreen was a source of constant irritation. Not only was the interior glass one of the most difficult parts to get a really good result on (looks fine inside the valeting bay, but take it outside in the sunlight and its a right mess!), but the design of the windscreen and dashtop area can make it so much harder because the base of the screen is so far away, and the angle so acute!.

"Thanks for that, will give that a try myself, Civic screen seems to always need cleaning and must be for that reason, I know the screen is ultra violet coated so it must just be the heat of the sun causing it"

Yes I had a Civic with a smeary screen, I had and still have all sorts of gadgets to reach the down the screen towards the top of the dash, triangular pads on telescopic sticks etc, but still had a smeary screen as soon as it's in the sun!