I have found using non ammonia glass cleaner like Stoner Invisible glass (
Home | Invisible Glass) inside and out using lots of clean microfiber towels resolves most glass issues. If that does not work you can use a non abrasive scouring powder like Bon Ami
https://www.bonami.com/product/bon-ami-powder-cleanser/or Bar Keepers friend
Soft Cleanser. Use the clean Microfiber towels or a sponge or the Scotch Brite Blue Non scratch scrub sponge
https://www.scotch-brite.com/3M/en_...4!e!!g!!scotch-brite non scratch scrub sponge . Stoner also makes a Glass stripping
Invisible Glass - 91411CSTON01 product but I have not used that yet. There are also water spot removal cleaners but I find the invisible glass spray works very well. Use it on the headlights and all other lights too. Only use the Non abrasive scouring powder on outside surface of the glass and only if the glass does not come clean using other methods. I have used that method on many of my older cars when nothing else worked. There was also a product that professional glass places use to polish glass using a special polishing disk and compound or a random orbital polisher but I have not heard about that process or if it is do able by a do it yourself process in a number of years.
When you clean the glass go vertically on one side and horizontal on the other (Horizontal on the inside of the hatch glass to avoid damaging the defroster and other grids) and you can see which side has the streaks and smudges. I learned that a number of years ago when I worked in car rental and it surprises a lot of people when they do it. It really helps to get the glass clean. You will be surpised at how grey the inside of your glass is!
When my glass looks like this I know it is time to do a complete through glass clean and I use the Invisible glass product. Spray the towel or the glass then wipe the glass dry then polish again with a dry clean towel. Turn the towel often during both steps.
Also clean or replace your wiper blades after you clean the glass. You could also after glass is clean apply RainX
https://www.rainx.com/original-glass-water-repellent/ but you will need to reapply it often.