On really nasty interiors I use IPA first on the inside of the windshield and finish with glass cleaner.
Interesting thread and comment Cee Dog.
On the Tahoe I recently finished detailing (cigar chain smoker) I first tried Meguire's glass cleaner (that's so highly praised here) and it wouldn't even begin to cut this stuff. Here's what I did:
It had gotten dark and I was running short on time. Since the rear windows were tinted black I decided to crawl inside the rear hatch with my trusty LED flash light and just take a look at the windows to see if the LED would allow me to see the dirt. It worked flawlessly and actually enhanced my ability to see what was being wiped off.
I started with Meguire's glass cleaner and applied it four different times to one window. Frustration was mounting, because I didn't have any other glass cleaner on hand because I didn't think I needed any (since Meg's glass cleaner is held in such high regard). Then I tried Meg's APC+ at 20:1 and with two passes it was able to remove this stubborn, thick (90,000 miles thick), nicotine residue. This meant a third pass (squirt down with Meg's glass cleaner to finish) was required to complete that one window. Still, that wasn't good enough for me.
I then remembered that I had a half gallon of 90% IPA in the house. I poured some in a sprayer and used it without diluting. To make this story short let me just say this. One spray down to remove all of the heavy nicotine and a second pass for a flawless finish. Mind you I used a LED flashlight and it allow me to see every single detail of the glass, whether it was clean or not that is. Usually early morning sun (as in the drive to work), or late evening sun (as in the drive home from work) is where we always discover the spots we missed.
Needless to say, I was thoroughly impressed with using straight 90% IPA on factory tinted windows with no issues. I say no issues with the tinting because I was somewhat concerned what it may do to the tint. I assume factory tinted glass is actual tinted glass and not some coating or plastic tint.
Another thing that's important to note with my above comments in using 90% IPA is that is was night time as previously mentioned, and it was only about 60-65 degrees outside. The cool tempertures caused the alcohol to not flash as quickly, allowing it more time to work on the crud. Next time I get a chance to clean some real dirty glass I'll clean the glass again at dark with the LED and I'll try and get some pictures to demonstrate the process.