Yes glass usually is a bit hard to keep streak free. I clean my glass every time i wash my car. I wash my car every week and a half no longer than that. I have two towels, first one i use to take off the majority of the water, then the second i spray glass cleaner on (rain x) and make sure to get it streak free. Do a few passes just to make sure. Regarding the product, i use rain x wich is actually a over the counter product that works good in my opinion, im hoping to give the other brands a try in the future like meguiars and poorboys, and so on. One thing i noticed though, is the more you take care of your glass the easier it is to maintain, so in other words if you dont clean your glass as often as i do it will be harder to keep clean, where as if you make it a weekly thing and do a good job every time, it will get easier and easier every time. Does that help?