If you came here expecting something about driving around nekkid, sorry to disappoint you: that's not the theme of this post. (Trust me when I say that nobody wants to see a guy my age tooling around in the buff.) This post is about cleaning car windows.
Among the many things I'm not good at (a very long list), washing car windows is a prominent item. I've tried glass cleaners, bleach-based cleaners, soap-and-water, plain water, even windshield washer solvent, and inevitably the windows end up with streaks. A bit of research turned up the fact that there are special purpose sprays, allegedly used by people who "detail" cars. I'm not that anal (and too cheap) to buy them. Fortunately, I've had a bit of luck recently, which I'm writing down here so that I won't forget it.
As a starting point, if the windows are really grungy, it's probably a good idea to wash off the bulk of the dirt with plain water, blotting stuff up with paper towels so that you don't leave mud caked on the windows. (Between endless road construction and my driving with the sun roof open, this is a nontrivial consideration, both exterior and interior.)
Next comes the secret elixir: vinegar and water. I read someplace that white vinegar works best, but I've been getting good results with apple cider vinegar, which is what I happen to have in the kitchen. The exact proportions of the mixture are a mystery to me, but I think it's safe to say more than half should be water. (Note to self: less vinegar next time. We're not making salad dressing.)
The other key tool is newspaper. For whatever reason, newpaper works better than even paper towels at both absorbing the dirt and not leaving streaks. I worried at first that the ink would bleed onto the windows, but that does not seem to be the problem. After a few brief experiments, it appears that (as with other uses) the New York Times does better than my local paper, but either will work. I'm not sure if really conservative papers will work as well; they may insist that you outsource the job. In any event, you'll want to read the paper before washing the windows with it.
One or two web sites talked about devoting a spray bottle to applying the mix, but that strikes me as overkill. Wad up one sheet of newsprint, dip one end in a bowl of the mix, and apply it. Wipe, and use the dry end to blot up any excess. Repeat as needed.
The results are not perfect, but they're better than anything I've achieved in the past.