2009 Honda CRV
 

I have a 2009 Honda CRV and for some odd reason my windshield gets fogged up with a greasy type film. I tried wiping it with my windshield wipers but not go. It is especially common in hot humid weather. Has anyone encountered such a thing and if so, how do you recommend I try to fix it? I have been to like 10 body shops (Honda ones as well) and no one could help me.