Windex has changed over the years - it's not as good now.
For nice windows:
1. Windex with paper towels to remove bugs and dirt. Gets the gross stuff off.
2. Use formula #3 with non-linting towels (polypropylene or equivalent) to remove the windex residue and clean to a tee.
Formula #3 is what i had after testing #1 and #2...... it's about 60% isopropyl alcohol, a few drops of Dawn, and the rest distilled water in a quart sized spray bottle. Works great, evaps fast, and smells neat to boot. Very therapeutic as a ritual to clean glass this way, and it will increase your driving enjoyment as you style past the posers in their Mega-cars.
1960 Cad Hearse