winshield cleaning

has anyone ever noticed in those small car dealerships, the cars that have an advertisement written with a paint marker or w/e on the winshield? well i bought one of those cars and they cleaned it off but i still see the marking on it in the morning when the winshield is all wet from morning mist. does anyone know how to remove it and with what.

there was stuff on my window that i bought to replace the deers head smashed one had writing on it, the guy who put the glass in got it off with a window scraper and some foam stuff, i think if u use windex, it might work, or u couild go to a car parts tore, they mighjt have some super cleaning glass cleaner

i think the stuff they use is grease based which is why just water doesnt clean it, use a degreaser of some sort and it should take care of it

thnx ima try both of those.. :)