I have been washing our vehicles for over 55 years and I have yet found a product that cleans the glass. I generally use the standard Windex and paper towels and in the shade the glass looks good but ...
After a good washing and rensing (I use Zymol car wash and wax)I clean all windows with Rainx (follow directions), does not streak and water beeds off. The unit still looks new. Both products can be purchased at any Wal-Mart.