Ok. I promised I would post results when I finished the job so here goes. I finally cleaned ALL of the junk off the front and back windows. It was simple and cheap but time consuming. First I 'dusted' the window with plain old Windex just so I could see where I was scrapeing. Then I lightly scraped the windows with a single edged razor blade, slightly overlappig each pass over the window. Then I cleaned the windows with Windex and a microfiber shop cloth( they're 20 for 10 bucks at Costco) Presto!! Crystal clear windows for the first time since I bought the car in October.