Try detailing clay. Use car wash soap/water for lube. Rub the glass with clay after wetting with soap/water. Turn and kneed the clay as it gets dirty just like you would if you were doing the paint.

I like to apply rainx after I clean the windshield like this.

Claying may work. I actually use the 50/50 alcohol /water solution on all the glass inside and out. It has removed pretty much everything over time. Not everything comes off the first time, but after a while it seem to come off. I had film on the outside from the wipers in the past and so far this approach has worked best for me. I now ask my indy and dealer not to clean the class as most commercial cleaners leave some kind of a film behind and it takes me a while to get it off completely using alcohol and water.

What kind of achohol ...regular rubbing or denature .....

I've read that using a 50/50 mixture of water and denatured alcohol in a spray bottle is an excellent window cleaner.
Some say to use crumbled up newspaper to clean the mixture while on the glass, and then use a clean newspaper to polish the glass.
Others say that microfiber towels work just as well. Use one to clean the wet glass, and a clean dry one to polish.

I'll be trying this myself as I too have that dreaded interior glass film.
My BMWs were never this bad.

Also, check your AC settings in "vehicle settings".
There is a box to check for auto recirculation.
I believe this setting is to allow the system to shut off outside fresh air when the system detects pollutants.
I turned this auto function off.
This should be a button on the HVAC controls and not inside the MMI settings menu.
Oh well. :)

Rubbing alcohol (Isopropyl), but 91% not the usual 70%.

the button above 'off' on right of hvac controls is the recirculation button, on/off

Just expanding on my post above. Haven't heard using denatured alcohol. Denatured alcohol is ethanol with additives. Ethanol leaves behind oil traces. Isopropyl is a better solvent, evaporates quicker and leaves nearly zero oil traces compared to ethanol. Isopropyl is especially good at dissolving oils, which is what ends up on the outside of the windshield from road grime and the plastic gasses on the inside.

That's the manual recirc button.
The one in the MMI settings is for the "auto" feature.

In my BMW's the auto and manual settings were on the HVAC section.
Looks like Audi put the "auto" setting in MMI for whatever reason.

With "auto" checked to be on, even if one manually selects recirc on or off the system will automatically select recirc when the system is programmed to do so, thus overriding the manual setting.
When the air is clear again it will, should, automatically go back to open/fresh air.

Personal experiences obviously vary.
I've never tried any type of diluted alcohol for cleaning windows.
Doing some reading I've seen recommendations for both denatured and isopropyl.

Your experience is certainly valid and appreciated. :)