There are two things I have learned about windshields that have helped me. Freeze the windshield - This one is not fun but it works really well and you will need your coat. Turn your defrost to cold and get the windshield as cold as possible by lowering your visors to hold the cold on the windshield. This will keep snow or ice from sticking to the windshield. Keep it as cold as needed to keep ice from forming. The second idea is to put the defrost on as hot as possible and lower the visors to hold the heat in and this will melt the wet snow that sticks to the top of the windshield. It just depends on what type of winter weather conditions you are driving in to what windshield tip will work best.