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 you have cleaned the dirt and bugs off, go over it real good with 0000 steel wool. This will get nearly all the tiny grit and water spots off then follow it up with a good glass cleaner and newspaper. Maybe it is the ink on the newspaper that makes it do such a good job of putting a good finish on the glass.